Microsite

A microsite is a small, tightly focused website that stands somewhat apart from your main site, with its own handful of pages and often its own domain name or look. They're a common choice for a single marketing campaign, product launch, or event.

The appeal of a microsite is freedom and speed: a microsite can move fast without dragging the whole content management system along. The risk of a microsite is sprawl, since every orphaned microsite is one more thing to maintain and secure, so it is worth deciding up front when each one ends.