Workspaces is a virtual desktop manager built into Ubuntu. It allows you to expand your working area using virtual desktops. You can have up to 4 individual workspaces running at the same time, which is really useful when multitasking.
Workspaces are by default disabled in Ubuntu, so here's how to enable them:
Click on System Settings and go to Personal > Appearance:
Select the Behavior tab and tick the Enable workspaces checkbox:
The Workspace Switcher shorcut will be added to the Launcher:
NB: You can also use the Ctrl + Alt + Left or Right arrow key combination to navigate through your opened workspaces.