App Store Optimization Glossary
Clear definitions of every term that matters in App Store keyword research — from keyword popularity and difficulty to storefronts, metadata fields, and competitor teardowns.
All glossary terms
- App Age / Tenure as a Ranking SignalAn app's time in the store, and the ranking history it accumulates during that time, functions as a form of algorithmic trust that new apps have to build up rather than start with.
- App Clip DiscoverabilityApp Clips are lightweight, instant-launch slices of an app triggered by a link, code, or NFC tag rather than App Store search, so conventional keyword ASO has little bearing on how they're discovered.
- App Preview VideoAn app preview video is a short, auto-playing (muted) video on the App Store product page and in some search placements, used to demonstrate the app in action and improve conversion.
- App Store AlgorithmThe App Store algorithm is Apple's automated system for ranking apps in search results — combining metadata relevance, user engagement signals, and quality indicators to determine which apps appear for each search query.
- App Store CategoriesApp Store categories are the classifications Apple uses to group apps in browse and featured views — category selection affects both discoverability in browse and how the search algorithm interprets keyword relevance.
- App Store Connect AnalyticsApp Store Connect Analytics is Apple's own native reporting on impressions, product page views, conversion, and retention for your app, distinct from and complementary to third-party ASO tools.
- App Store Conversion RateApp Store conversion rate is the share of users who see your app's listing in search or browse and go on to install it, and it now carries as much ranking weight as metadata relevance in most categories.
- App Store Metadata FieldsApp Store metadata fields are the text inputs that affect how an app is discovered and presented in the App Store — primarily the name, subtitle, keyword field, and developer name, each with different character limits and ranking weight.
- App Store Optimization (ASO)App Store Optimization is the process of improving an app's visibility in App Store search results and its conversion rate from search impressions to installs.
- App Store Search Ranking FactorsApp Store search ranking factors are the signals Apple's algorithm uses to determine which apps appear at the top of results for a given keyword — primarily metadata relevance, user engagement, and app quality indicators.
- App Store StorefrontAn App Store storefront is one country-specific instance of the App Store, each with its own search demand, ranking results, and keyword difficulty — 109 storefronts exist in total.
- Apple Search AdsApple Search Ads is Apple's paid advertising platform for the App Store, allowing developers to bid on keywords to display their app at the top of search results.
- ASO A/B TestingASO A/B testing (also called product page optimization) is the practice of testing alternative versions of app store creative elements — icons, screenshots, descriptions — to improve conversion from search impression to install.
- ASO AuditAn ASO audit is a structured review of an app's current metadata, keyword coverage, competitive position, and store presence to identify gaps and improvement opportunities.
- ASO Keyword ResearchASO keyword research is the systematic process of identifying, scoring, and selecting the App Store keywords most likely to deliver organic installs given your app's current competitive position.
- Brand Campaign (Apple Search Ads)A Brand campaign is an Apple Search Ads campaign that bids Exact Match on your own app and company name terms, defending them from competitors at the lowest cost per tap of any campaign type.
- Branded vs. Non-Branded KeywordsBranded keywords include an app or company name; non-branded keywords describe a problem or category without naming a specific product — the distinction matters for measuring organic discovery versus brand recall.
- Burst CampaignsA burst campaign is a short, high-intensity user acquisition push designed to generate enough installs in a brief window to boost an app's ranking for target keywords, leveraging the ranking algorithm's sensitivity to install velocity.
- Category Campaign (Apple Search Ads)A Category campaign is an Apple Search Ads campaign that bids Exact Match on the non-branded genre terms describing what your app does, aimed at users actively searching for that type of app.
- Competing Apps CountThe competing apps count is the number of apps that appear in search results for a given keyword in a specific storefront — a proxy for how saturated that keyword's search results are.
- Competitor TeardownA competitor teardown in ASO is the process of identifying which keywords a competing app ranks for — revealing their strategy and surfacing terms you may have missed.
- Cross-LocalizationCross-localization means targeting a keyword's real demand from a storefront where it isn't the dominant language — for example, capturing English-language searches inside a bilingual or English-fluent non-English-primary market.
- Custom Product Pages (CPP)Custom Product Pages let you create up to 35 alternate versions of your App Store listing, each with its own screenshots and preview video, to link from specific marketing campaigns or audiences.
- Deciding Which Keywords to Bid On vs. Rank ForChoosing between paying for a keyword through Apple Search Ads and earning it organically depends on the keyword's difficulty, your current ranking, and whether paid spend or metadata effort gets you there faster.
- Discovery CampaignA Discovery campaign is an Apple Search Ads campaign type built to surface new, unknown keywords by running Broad Match and Search Match against a wide audience rather than a fixed keyword list.
- Download VelocityDownload velocity is the rate of installs an app receives over a short window, treated by Apple's ranking algorithm as a multiplier alongside metadata relevance, conversion, and retention.
- Editorial Badge Impact ('App of the Day' and Featured Badges)Editorial badges like 'App of the Day' come from Apple's curatorial process, not from ASO metadata, but the install spike they generate can indirectly affect keyword ranking through download velocity.
- Editorial FeaturesEditorial features are the app stories, collections, and highlights Apple's own editorial team selects across the App Store, entirely separate from the algorithmic search and browse ranking that ASO work influences.
- Feature Graphic / Preview Assets (ASO)Preview assets — screenshots and app preview videos — are the visual elements that appear in search results and product pages, directly affecting the conversion rate from impression to install.
- Halo Effect (Paid-to-Organic Spillover)The halo effect describes organic App Store installs that increase as a side effect of running paid Apple Search Ads, driven by paid-install velocity lifting an app's ranking and visibility for the same keyword.
- Impression-to-Product-Page-View RateImpression-to-product-page-view rate measures how many users who see your app in search or browse results go on to open the full product page, the step immediately before the install decision.
- In-App Purchase KeywordsIn-App Purchase (IAP) names and descriptions are indexed by Apple for search — giving apps an additional, often overlooked, source of keyword coverage beyond the main metadata fields.
- Incrementality Testing (ASO)Incrementality testing isolates what a specific ASO change or ad campaign actually caused, as distinct from installs that would have happened anyway, by comparing against a holdout or a paused period.
- Keyword CannibalizationKeyword cannibalization in ASO occurs when an app's multiple metadata fields target the same keyword, wasting limited character space rather than covering additional search terms.
- Keyword DifficultyKeyword difficulty is a 0–100 score estimating how hard it is to break into the top-ranking positions for a given App Store keyword, based on the strength of apps currently holding those positions.
- Keyword Gap AnalysisA keyword gap analysis identifies terms that competitors rank for but your app does not — surfacing targeting opportunities you haven't yet captured.
- Keyword Indexing TimeKeyword indexing time is the delay between submitting a metadata update and Apple's search index reflecting the new title, subtitle, or keyword field.
- Keyword Match Types (Exact vs. Broad)Exact Match and Broad Match are the two ways Apple Search Ads ties a keyword you enter to the searches your ad actually appears for — Exact targets close variations of the term, Broad expands to related phrases and synonyms.
- Keyword PopularityKeyword popularity is a 0–100 score measuring how often users search for a given term in the App Store, derived from Apple Search Ads demand signals.
- Keyword Relevance vs. PopularityRelevance is Apple's internal judgment of whether a keyword genuinely matches your app's metadata; popularity is a separate measure of how much total search demand that keyword has — a term can score high on one and low on the other.
- Keyword SeasonalityKeyword seasonality describes the predictable rise and fall of search demand for certain App Store keywords based on time of year, events, or cyclical patterns.
- Keyword StuffingKeyword stuffing is repeating or jamming keywords into App Store metadata beyond what natural, readable copy would contain — a practice Apple's algorithm penalizes rather than rewards.
- Localization (ASO)ASO localization is the process of writing separate app metadata (name, subtitle, keyword field) in the local language of each target App Store storefront to capture search demand that English-only metadata misses.
- Long-Tail KeywordsLong-tail keywords are multi-word, specific search phrases that individually have lower search volume than broad terms but collectively cover the majority of App Store searches and often have much lower ranking difficulty.
- New App Keyword Strategy (Cold Start)A new app with few or no ratings needs a different keyword strategy than an established one — targeting lower-difficulty terms first to build the ranking history and engagement signals that later unlock more competitive keywords.
- Niche KeywordsNiche keywords are terms specific enough to describe a well-defined subset of App Store users — they have moderate-to-low popularity scores but often dramatically lower difficulty than the broad category terms.
- Organic vs. Paid InstallsOrganic installs come from users who found an app through unpaid search or browse; paid installs come from Apple Search Ads or other ad campaigns — the distinction matters for measuring ASO's real impact separately from ad spend.
- Plural and Singular KeywordsApple's App Store search treats common plural and singular forms of a word as equivalent for most terms, which means including both usually wastes character space rather than adding coverage.
- Portfolio Keyword CannibalizationPortfolio keyword cannibalization happens when a studio's multiple apps target the same keywords, splitting the same search demand between the studio's own apps instead of capturing a wider set of terms.
- Product Page Optimization (PPO)Product Page Optimization is Apple's native App Store Connect A/B testing tool, letting you run up to three alternate treatments of your icon, screenshots, and preview video against your default page for up to 90 days.
- Promotional TextPromotional text is a 170-character field shown on the App Store product page that can be updated at any time without a new app submission, but it is not indexed for search.
- Ratings and Reviews (ASO Impact)App Store ratings and review count are quality signals that influence search ranking — higher rating counts correlate with higher ranking for competitive keywords, independent of rating score alone.
- Retention Rate (as a Ranking Signal)Retention rate — the share of users who keep using an app after install — is now treated as a first-class App Store ranking signal alongside metadata relevance, download velocity, and conversion.
- RTL (Right-to-Left) Language ASORight-to-left languages like Arabic and Hebrew require App Store metadata, screenshots, and layout consideration adapted for RTL reading direction, not just word-for-word translation.
- Screenshot Caption IndexingSince June 2025, Apple has used OCR to read the text overlaid on App Store screenshots and treats that caption text as an additional ranking signal, distinct from the metadata fields developers fill in directly.
- Search Autosuggest / AutocompleteSearch autosuggest is the list of suggested queries the App Store search bar shows as a user types, generated from real aggregate search behavior and usable as a free source of keyword candidates.
- Search MatchSearch Match is an Apple Search Ads feature that automatically matches your ad to relevant user searches based on your app's existing metadata, without you entering any keywords.
- Search Tab vs. Browse TabThe App Store's Search tab surfaces apps by keyword query, where ASO metadata directly applies; the Today, Games, and Apps browse tabs surface apps through editorial curation and category browsing, where it doesn't.
- Seasonal Keyword CalendarA seasonal keyword calendar maps the recurring windows when specific App Store categories see predictable demand spikes, so metadata updates can be timed ahead of the peak rather than during or after it.
- Single Keyword vs. Keyword PhraseIn the App Store keyword field, single words are indexed individually and recombined by Apple's algorithm, which changes how you should weigh one broad word against a specific multi-word phrase.
- Tap-Through Rate (TTR)Tap-through rate is the share of users who see your app in App Store search results and tap into the product page, measuring the pull of your icon, name, and subtitle before any conversion decision is made.
- Title vs. Subtitle KeywordsIn App Store Optimization, keywords in the app title carry the highest ranking weight; subtitle keywords carry secondary weight — both are more impactful than the keyword field.
- Today Tab FeaturingThe Today tab is Apple's editorially curated App Store home surface, distinct from search results and unaffected by keyword metadata or ASO work.
- Translation vs. LocalizationTranslation converts words from one language to another; localization adapts the message, keyword choices, and cultural framing for how people in that specific market actually search and read.
- Update Frequency as a Quality SignalHow often an app ships updates is read by both users and, to some extent, the App Store algorithm as an indicator of active maintenance and quality, separate from any specific metadata change in a given release.
- What's New TextWhat's New text is the release-notes field shown for an app update — it is not indexed for search, but it can affect a user's decision to update or reinstall.
Practical guides applying these concepts
Ready to apply these definitions to real keyword research workflows? Read our in-depth guides:
- How to Find Low-Competition App Store KeywordsA practical step-by-step method for finding App Store keywords with real search demand and low enough difficulty to rank for — without guessing.Read guide
- How to Do App Store Keyword Research: A 4-Phase WorkflowA complete, repeatable workflow for App Store keyword research — from ideation to metadata update — for indie developers and ASO professionals.Read guide
- How to Evaluate App Store Keyword DifficultyWhat keyword difficulty actually measures, how to interpret scores in context, and how to set realistic targets based on your app's current authority.Read guide
- Free vs. Paid App Store Keyword Research ToolsWhat free ASO keyword tools can and can't do, when a paid tool earns its cost, and how to decide what's right for your stage of development.Read guide
Put the definitions to work
Score App Store keywords by popularity and difficulty across 109 storefronts — the two numbers behind every definition in this glossary.
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