Definitions for every metadata, SEO, and platform term you'll encounter as a creator, stock contributor, or ecommerce seller — with practical context for how each term applies to real platforms.
Last updated: April 17, 2026 · 65 terms defined · A–W
Metadata vocabulary is scattered across SEO guides, platform help docs, and developer documentation. A term like "keyword" means something different on Adobe Stock than it does in a Shopify product listing or a YouTube description. A "tag" on Etsy is a ranked search signal; a "tag" in HTML is a structural element; a "tag" in Redbubble is a searchable label — same word, three different things.
This glossary consolidates every term you need, with definitions written for creators and sellers rather than developers. Where a term works differently across platforms, those differences are called out explicitly.
How to use this glossary: Use the alphabet navigation to jump to a letter section, or use Ctrl+F / Cmd+F to search for a specific term. Each entry includes practical context — not just a definition, but how the term matters in your actual workflow.
A text attribute added to an HTML <img> tag that describes the visual content of an image. Serves two purposes: accessibility (screen readers read it aloud for visually impaired users) and SEO (Google reads it to understand what an image depicts). Written in the alt="" attribute: <img src="photo.jpg" alt="ceramic coffee mug with blue glaze on white background">.
On Instagram, you can add alt text manually to posts via the advanced settings menu. On Shopify, every product image has an alt text field. On Adobe Stock, the image title functions similarly to alt text in that it describes image content for search indexing.
Good alt text is descriptive and specific, not generic. "Product image" is not alt text; "handmade silver hoop earrings with turquoise inlay on white background" is.
The set of rules and signals a platform uses to decide which content to show, to whom, and in what order. Every platform — YouTube, Etsy, Instagram, TikTok, Google — has its own algorithm with unique ranking factors. Metadata is one input to an algorithm; engagement signals, account history, and content freshness are others.
Understanding which metadata fields each platform's algorithm actively indexes is the core skill of platform SEO. See the Platform Metadata Comparison for a breakdown of what each algorithm actually reads.
The visible, clickable text in a hyperlink. When someone links to a page using the words "Etsy SEO guide," those words are the anchor text. Google uses anchor text as a signal about what the linked page is about, which influences how that page ranks for related queries.
For creators managing a blog or knowledge base (like this one), writing descriptive anchor text when linking between articles helps Google understand topical relationships between pages.
A schema.org markup type (@type: "Article") added to blog posts and editorial content to tell Google the page is an article. Signals include headline, datePublished, dateModified, author, and publisher. While Article schema isn't a direct ranking factor, it helps Google correctly categorize the page and can surface it in Google News and Discover feeds. Often implemented in JSON-LD format in the <head> of the page.
A hidden metadata field in Amazon Seller Central that buyers never see but Amazon's A9/A10 algorithm indexes. Also called "search terms" or "hidden keywords." The field accepts up to 250 bytes (not characters — multi-byte characters like accented letters count as 2 bytes). Commas are optional; spaces separate terms.
Best practice: use backend keywords for synonyms, alternate spellings, common misspellings, and long-tail variations that don't fit naturally in your visible listing copy. Do not repeat terms already in your title or bullet points — Amazon already indexes those. Do not use competitor brand names.
A navigational element showing a user's location within a site hierarchy. Example: Home › Blog › Metadata Glossary. Breadcrumbs improve user experience by showing context and providing quick navigation back to parent pages. Google reads breadcrumbs to understand site structure and sometimes displays them in search results instead of the full URL.
A schema.org markup type that explicitly defines a page's breadcrumb path in structured data. When implemented, Google may display the breadcrumb path in search results instead of the raw URL, which improves readability and click-through rates. Defined as a list of ListItem elements, each with a position, name, and URL.
The text accompanying a social media post — the primary metadata field on Instagram, TikTok, and Facebook. On Instagram and TikTok, captions are capped at 2,200 characters. On Facebook, the practical limit is much higher (63,206 chars) though most effective posts are considerably shorter.
The first line of a caption is the most visible — it appears in feed before the "more" truncation. This line functions similarly to a title tag: it should communicate your core message or hook immediately. Hashtags are typically placed within the caption on TikTok or at the end of captions on Instagram.
A canonical tag (<link rel="canonical" href="...">) tells Google which URL is the "preferred" version of a page when multiple URLs serve similar or identical content. This prevents duplicate content issues — for example, if your product page exists at both /products/earrings and /products/earrings?color=silver, the canonical points Google to the main URL to index.
Every page on a well-built website should have a self-referencing canonical tag even if there's no duplicate content, as a best practice signal.
A classification field on stock photography platforms that places an image or video into a broad topical bucket. Adobe Stock uses 24 categories including Architecture, Business, Education, Nature, People, and Technology. Category selection affects which browse feeds and curated collections your work appears in. It is a hard filter — contributors should select the most accurate category, not the most popular one.
The percentage of people who click on your result or listing after seeing it. Calculated as: (Clicks ÷ Impressions) × 100. A high CTR tells algorithms that your title and thumbnail/image are compelling relative to competing results. On Amazon and Etsy, CTR is a significant ranking factor — it signals to the marketplace that your listing satisfies buyer intent. In Google Search, CTR indirectly influences ranking over time.
Improving metadata (especially titles and descriptions) is the primary lever for improving CTR without changing the underlying content.
A text field for longer content about a product, image, listing, or video. What "description" means varies significantly by platform:
The degree to which a piece of content or a listing can be found by people who are not already looking for it specifically. High discoverability means appearing in search results, category feeds, recommendation systems, and hashtag pages for relevant queries. Metadata is the primary tool for improving discoverability — you cannot be found for terms you haven't included in your indexable fields.
Exchangeable Image File Format data — technical metadata embedded directly into image files by cameras and smartphones at the moment of capture. EXIF data includes: camera make and model, lens focal length, aperture, shutter speed, ISO, GPS coordinates, date/time, and orientation. It is stored inside the image file itself, not in the surrounding webpage.
Adobe Stock reads EXIF data as part of contribution review — it can flag AI-generated images that have been submitted as authentic photography. Google can read EXIF GPS data, which it uses for local search and Google Maps integration. For privacy, creators sometimes strip EXIF data before publishing to avoid revealing location information.
A licensing category for stock images depicting real people, places, or events in news, documentary, or educational contexts — where a model release or property release was not obtained. Editorial images can only be used in news, blogs, and editorial publications — not in advertising or commercial contexts. If an image shows identifiable people in public settings (protests, sports events, news scenes), it typically must be flagged as editorial. Failing to flag editorial content correctly is a common reason for contributor rejection.
A measure of how actively an audience interacts with content, calculated as total engagement actions (likes, comments, shares, saves, clicks) divided by reach or follower count. Platforms use engagement rate as a proxy for content quality and audience relevance. High engagement signals to the algorithm that a piece of content is worth distributing to a wider audience. Metadata that accurately represents content (correct hashtags, accurate titles) attracts the right audience, which tends to produce higher engagement rates.
A schema.org markup type that marks up a page's FAQ content in structured data. When Google validates it, the FAQ questions and answers can appear as expandable dropdowns directly in search results, taking up significantly more SERP real estate and improving visibility. Implemented in JSON-LD with Question and Answer types nested within the FAQPage type. Best used on pages that have genuine, unique answers — not thin or repeated Q&A content.
A highlighted answer box that appears above traditional search results (position "0") in Google search. Featured snippets pull a short excerpt — a paragraph, a list, or a table — from a webpage that Google determines best answers the search query. Winning a featured snippet dramatically increases visibility and CTR. To target featured snippets, structure content to directly answer specific questions with clear headings and concise answers within the first few paragraphs of a section.
A word or phrase preceded by the # symbol, used to categorize content into topical feeds and make it discoverable to users searching or following that topic. Hashtag behavior varies significantly by platform: Instagram treats hashtags as primary discovery signals (up to 30 allowed); TikTok embeds them in the caption for distribution signals; Pinterest treats them similarly to keywords (use 2–5); Facebook has minimal algorithmic support for hashtags; X limits effective use to 1–2 per post.
Hashtag strategy — using the right size hashtags for your account, mixing niche and broad, researching hashtag volume — is a distinct skill from keyword research, though the underlying logic (matching content to how users search) is similar.
A schema.org markup type for step-by-step instructional content. When validated by Google, HowTo schema can enable rich results showing individual steps in the search result. Includes step name, text description, image, and optionally time and tool requirements. Most effective for tutorial and instructional content where users benefit from seeing the steps before clicking.
The structured use of HTML heading tags — H1 (page title), H2 (section headers), H3 (subsection headers) — to organize content. Google uses headings as strong relevance signals for understanding page structure and topic coverage. The H1 should contain the primary keyword and appear exactly once per page. H2s should cover the main subtopics and often appear as standalone answers in featured snippets. Proper heading hierarchy also improves accessibility for screen readers.
The practice of optimizing images so they rank in Google Image Search and contribute to the overall SEO of a webpage. Key elements: descriptive file names (use hyphens between words), accurate and specific alt text, appropriate file size (large images slow page load, hurting Core Web Vitals), correct image format (WebP preferred for web), and structured data markup using ImageObject schema. High-quality image SEO is especially important for ecommerce and stock photography sites where images are the primary content.
The process by which a search engine or platform crawls a page or piece of content and adds it to its database so it can appear in search results. A page must be indexed to rank. Indexing issues — caused by noindex tags, blocked robots.txt rules, duplicate content, or thin content — prevent pages from appearing in search entirely. On marketplace platforms, "what the algorithm indexes" refers to which metadata fields are read and used for search matching.
Links between pages on the same website. Internal links serve two purposes: they help users navigate and discover related content, and they pass "link equity" (PageRank) between pages. Pages with many internal links pointing to them are signals to Google that those pages are important. For creator websites, blogs, and knowledge bases, a strong internal linking strategy — connecting related articles with descriptive anchor text — significantly improves the ranking ability of all pages on the site.
The percentage of times a keyword appears relative to the total word count of a page. Historically over-weighted as a ranking signal, keyword density is now largely irrelevant as a metric — modern algorithms understand context and semantic relevance, not raw frequency. Keyword stuffing (unnaturally repeating a keyword to inflate density) actively hurts rankings. Write naturally; include your primary keyword in the title, H1, and opening paragraph, then let the topic guide the rest.
The process of identifying the specific words and phrases that your target audience uses when searching for content, products, or images like yours. Keyword research informs every metadata decision — which words to use in your YouTube title, which tags to add to your Etsy listing, which keywords to include in your Adobe Stock submission. Tools used for keyword research include Google Keyword Planner, Ahrefs, SEMrush, Etsy's own search bar, and YouTube's autocomplete. The goal is to find keywords with meaningful search volume and achievable competition levels.
The primary search field on stock photography platforms. On Adobe Stock, up to 50 keywords describe the visual content, mood, style, colors, composition, subjects, and use cases of an image. Unlike tags on social platforms, stock keywords carry approximately equal weight — there is no "primary keyword." They should be accurate, specific, and varied (don't repeat similar words). Poor keyword selection is the leading cause of low visibility on stock platforms.
A keyword phrase of three or more words that is more specific and typically lower in search volume than broad "head" keywords — but also lower in competition and higher in purchase or action intent. Example: "ceramic coffee mug" is a head keyword; "handmade ceramic coffee mug with blue glaze gift" is a long-tail keyword. Long-tail keywords are disproportionately valuable for small sellers and new creators because they can rank faster, attract more qualified buyers, and convert better. Etsy tags and Amazon backend keywords are natural homes for long-tail keyword phrases.
A marketplace product page — the complete unit of content including title, description, images, price, tags/keywords, and attributes. On Etsy, each listing has its own metadata and SEO performance. On Amazon, a listing is called a "product detail page" and includes the ASIN, title, bullets, description, backend keywords, and A+ content. Optimizing a listing means improving all metadata fields together for maximum discoverability and conversion.
Literally "data about data." Metadata describes the attributes of a piece of content — what it is, who made it, when it was created, what it contains, what it's about. A photo's metadata includes its title, keywords, EXIF data, copyright notice, and alt text. A YouTube video's metadata includes its title, description, tags, and upload date. A product listing's metadata includes its title, description, keywords, and category. Metadata is what makes content findable, classifiable, and understandable to both humans and algorithms.
An HTML tag (<meta name="description" content="...">) that provides a summary of a page's content for search engines. Google often uses this text as the description snippet shown below a title in search results — though it can override it with text from the page body if it deems the page content more relevant. Optimal length is 150–160 characters. A well-written meta description improves CTR by communicating the page's value proposition clearly. It is not a direct ranking signal but indirectly affects rankings through CTR.
The HTML <title> tag — the single most important on-page SEO element. It appears in browser tabs, search results, and social sharing previews. Google truncates titles in search results to approximately 55–60 characters (600 pixels). Best practice: include your primary keyword near the beginning, keep it under 60 characters, and write it to be compelling to human readers, not just keyword-stuffed. On Shopify, the meta title for a product is set separately from the product title, in the "Search engine listing preview" section.
A keyword specific to a narrow topic, community, or product category. Niche keywords have lower search volume but attract a highly targeted audience. On stock platforms, niche keywords (e.g., "cottagecore aesthetic flatlay" vs. "flowers") attract buyers with specific creative visions — and because fewer contributors use precise niche terms, there's less competition. For Etsy sellers, niche keywords often align with specific buyer personas, occasions, or aesthetic movements (cottagecore, dark academia, goblincore).
A protocol (developed by Facebook, now universal) that uses HTML meta tags to control how a URL appears when shared on social media. Key OG tags: og:title (title shown in the link card), og:description (summary text), og:image (the preview thumbnail), og:url (canonical URL), and og:type (article, website, etc.). Without OG tags, social platforms make their best guess at what to show — often with poor results. OG tags are especially important for blog posts, product pages, and any content designed to be shared.
The number of people who see a piece of content without paid promotion. On social platforms, organic reach has declined significantly over the past decade as platforms prioritize paid advertising. On search engines, organic reach refers to traffic from unpaid search results. Good metadata improves organic reach by making content more discoverable in search and recommendation systems without paid amplification.
A page with no internal links pointing to it from anywhere else on the site. Orphaned pages are difficult for both users and Google to discover — Google's crawler may not find them at all if they're not in a sitemap. Every page on a site should be reachable through at least one internal link. Knowledge base articles and blog posts should link to each other using topically relevant anchor text.
A comprehensive, authoritative page covering a broad topic in depth, surrounded by a cluster of related "spoke" pages that cover subtopics in detail. The pillar page links to all spoke pages; spoke pages link back to the pillar. This topic cluster structure helps Google understand topical authority. For a site like Metadata Reactor, a pillar page might be "The Complete Metadata Guide" with spoke pages covering each platform's specific metadata requirements.
See Algorithm. The term "platform algorithm" specifically refers to the ranking and recommendation system of a particular platform (YouTube's algorithm, Etsy's Cassini algorithm, TikTok's FYP algorithm) as distinct from Google's search algorithm. Platform algorithms differ from web search algorithms because they also factor in engagement data, account history, and time-on-platform metrics that Google cannot measure.
The body text on a product page or marketplace listing that describes a product's features, benefits, materials, dimensions, and use cases. On Amazon, product descriptions (2,000 chars) are indexed but weighted below the title and bullet points. On Shopify, the product description is fully indexed by Google. On Etsy, the description is not heavily indexed for Etsy's own search but is critical for Google Shopping traffic. Good product descriptions answer the unasked questions a buyer has before purchasing.
Any signal that a search algorithm uses to determine the order in which results are shown. Google uses hundreds of ranking factors; key ones include content relevance, page authority (backlinks), Core Web Vitals (page speed), mobile-friendliness, and user engagement signals. On Etsy, ranking factors include listing quality score, recency, conversion rate, and shipping speed. Metadata fields are ranking factors — optimizing them directly improves where you appear in results.
A platform-assigned score measuring how well a piece of content, listing, or ad matches a given search query or audience segment. High relevance scores lead to better placement. Relevance is calculated from metadata match (do your keywords align with the query?), engagement signals (do people click, save, buy?), and historical performance. On Facebook Ads, relevance score directly affects ad cost and delivery. On Etsy, relevance is the first filter in the Cassini algorithm before other factors like conversion rate are applied.
Enhanced search results that display additional information beyond a standard blue link — star ratings, FAQ dropdowns, recipe card thumbnails, event details, product prices. Rich results are powered by schema.org structured data markup. They occupy more space in search results and typically achieve higher click-through rates than standard results. Not all schema types generate rich results; Google documents which types are eligible in its Rich Results guidelines.
Code added to a webpage's HTML (typically in JSON-LD format inside a <script type="application/ld+json"> tag) that uses schema.org vocabulary to explicitly describe the page's content type and attributes to search engines. Common types used by creators: Article, Product, FAQPage, HowTo, BreadcrumbList, ImageObject, VideoObject. Schema markup is not a direct ranking factor but enables rich results, improves entity understanding, and helps Google correctly categorize content.
The underlying reason behind a search query — what the searcher actually wants to accomplish. The four main categories: informational (learn something), navigational (find a specific site), commercial investigation (research before buying), and transactional (buy something now). Writing metadata that matches the correct search intent is critical: a product page optimized for informational queries will convert poorly, while an informational guide page optimized for transactional queries will rank poorly. Align your content type and metadata to the intent of the queries you're targeting.
The practice of optimizing content, technical structure, and authority signals so that pages rank higher in search engine results pages (SERPs) for relevant queries. For creators and sellers, SEO encompasses three layers: on-page SEO (metadata, headings, content quality), technical SEO (page speed, crawlability, structured data), and off-page SEO (backlinks, brand mentions). Platform SEO — optimizing listings on Etsy, YouTube, Amazon — follows similar principles but with platform-specific rules and ranking factors.
The part of a URL that comes after the domain and identifies a specific page. In metadatareactor.com/blog/metadata-glossary/, the slug is metadata-glossary. Good slugs are short, keyword-rich, and use hyphens to separate words. Avoid slugs with auto-generated IDs (like /p?id=3847), dates, or stop words. On Shopify, the slug is called the "URL handle." On WordPress, it's set in the "Permalink" field. Slugs contribute to page SEO and should not be changed after a page is indexed without setting up a redirect.
Any data that is organized in a consistent, machine-readable format. In SEO, "structured data" typically refers to schema.org markup added to a webpage to help search engines understand its content. JSON-LD (JavaScript Object Notation for Linked Data) is the recommended format — it's placed in a script tag in the page head, separate from the visible HTML. Structured data is distinct from your visible content — it's a machine-readable layer that augments it.
Discrete labels applied to content that function as search and categorization signals. The meaning and weight of "tags" differs significantly by platform:
See Meta Title. The HTML <title> tag is the single highest-weight on-page SEO element. Not to be confused with a product title, video title, or listing title — though those fields often share the same value, they serve different purposes. The HTML title tag is specifically what appears in browser tabs and Google search results; platform-native title fields (like Etsy listing title or YouTube video title) power platform-internal search.
A content architecture model where a central pillar page covers a broad topic and links to multiple spoke pages covering related subtopics — each of which links back to the pillar. Topic clusters help Google understand a site's topical authority. For a metadata and platform SEO site, a cluster might look like: Pillar — "Complete Guide to Platform Metadata" → Spokes — YouTube Metadata, Etsy Metadata, Adobe Stock Metadata, Instagram Metadata, etc. Each spoke page deepens coverage; the pillar provides the authority center.
The format and composition of a webpage's address. Good URL structure is short, descriptive, keyword-containing, and hierarchical. Example of a good URL: metadatareactor.com/blog/etsy-seo-guide/. Example of a poor URL: metadatareactor.com/p?cat=3&id=47293. URL structure signals to both users and Google what a page is about. Use lowercase letters, hyphens between words (not underscores), include keywords, and avoid unnecessary parameters or subdirectories. Keep URLs stable — changing them after indexing without redirects destroys link equity.
The average amount of time viewers watch a YouTube video, often expressed as a percentage of total video length (Audience Retention). YouTube's algorithm heavily weights view duration as a quality signal — a video that holds 60% of viewers through to the end will consistently outrank a video that loses 80% of viewers in the first minute, even if the latter has more views. Metadata affects view duration indirectly: accurate titles and thumbnails attract viewers with genuine interest in the content, who tend to watch longer. Misleading titles may generate clicks but create high early drop-off, which hurts ranking.
Image metadata is all the descriptive and technical data associated with an image file. It exists at multiple levels:
For SEO and discoverability purposes, platform metadata and page-level metadata are more actionable than embedded metadata — they're what search engines and platform algorithms actually read most reliably.