WordPress Multisite is a core WordPress feature that turns one installation into a network of sites: one codebase, one database, one dashboard, many websites. Themes and plugins install once at the network level; users can have roles across sites. It’s how organizations run dozens or hundreds of related sites without maintaining dozens of separate WordPress installs.
Typical use cases: universities with departmental sites, franchises with location sites, media groups with multiple publications, and agencies managing branded microsites. If the sites share ownership, design systems, and administration, Multisite turns maintenance from N jobs into one.
The costs: all sites share the same plugin versions and go down together if the network does; plugin compatibility needs checking (most support Multisite, not all); and separating one site out later takes real migration work. For unrelated sites with different owners, separate installs remain the safer call.
