App Store Connect is Apple's suite of tools for submitting and managing apps on the App Store — per-localization metadata, pricing and releases, analytics, and responses to ratings and reviews.
Every App Store listing is edited in App Store Connect. For each localization it holds the fields that rank — app name, subtitle, and the 100-character keyword field — alongside the description, screenshots, app previews, and What's New text. Most of these changes ship with a new app version submitted to App Review; promotional text is the exception and can be edited at any time. The same account sets pricing and availability, pre-orders, and phased releases, and runs TestFlight. Apple Ads (formerly Apple Search Ads) is managed separately, in its own console. Google Play's counterpart is Play Console.
For ASO, App Store Connect is both control panel and scoreboard. The conversion and discovery levers live there — product page optimization tests, custom product pages, in-app events, promoted in-app purchases, featuring nominations, and App Store Tags — and so does App Analytics, which reports impressions, product page views, conversion rate, and downloads by source type. The Ratings and Reviews section is where teams read and publicly answer reviews. The App Store Connect API exposes much of the same surface, so teams can script metadata updates and review responses instead of working screen by screen.
Example
A language-learning app's growth lead starts the week in App Store Connect: checking last week's conversion rate by source type in App Analytics, drafting a featuring nomination for an upcoming course launch, and queuing new keyword-field copy for the German localization to ship with Thursday's app update.