Spaces

Spaces is a Mac OS X application introduced with OS X 10.5 that lets you run up to sixteen virtual desktops to organise your screen real estate. It can be triggered via a Hot Corners setting and becomes full screen when opened. The system preferences stay the same on each virtual desktop. However, windows can be moved between desktops. Error messages cannot be moved between virtual desktops, but besides this are treated as normal windows and stay in the same desktop.

In 2011 with the release of OS X 10.7, it was replaced by Mission Control which combines Spaces with Exposé.