Accounts, properties and data streams

GA4 has a three-level hierarchy.

• An account is the top-level container, usually one per company. It owns billing-style settings such as data-sharing options and account-level user access.
• A property is where data lives and reports are built. One property normally equals one business or product, and it can combine a website and its mobile apps. Time zone, currency, data retention, key events, audiences and custom definitions are all property settings.
• A data stream is a source of events inside the property: a web stream for a site, an iOS or Android stream for an app. A web stream has a measurement ID that looks like G-ABC123XYZ; that is what the tag on your pages sends to.

A common mistake is creating one property per website section or per country when you want to compare them in one report. Use a single property and split with dimensions (hostname, page path, country) instead; you cannot report across properties without BigQuery or a 360 roll-up property.

The Admin section (gear icon, bottom left) is split into an Account column and a Property column. Under Property you will spend most of your time in Data collection and modification (data streams, data filters, retention, deletion requests), Data display (events, key events, audiences, custom definitions, channel groups, attribution, reporting identity, DebugView) and Product links (Google Ads, Search Console, BigQuery).

Each web stream also has Configure tag settings, where tag-level behaviour such as internal traffic rules, cross-domain lists and session timeout is defined.