Site Collection

A site collection in SharePoint is a top-level site and its subsites, sharing the same content database, permissions root, and content types. In SharePoint Online (modern), every modern site is its own site collection — the older pattern of nested subsites under a single site collection is deprecated. Each site collection has its own URL path (sites/teamname or teams/teamname), independent storage quota, and lifecycle. Site collection administrators have full control over the site collection regardless of inherited permissions. Replaced largely by the site concept in modern SharePoint, where the distinction matters less than it once did, though the term persists in admin UIs and PowerShell.