A build area is the physical location where a build takes place. A build area can be a Dimensions work, deployment, or library cache area:
A work area is an area on your hard drive or a remote node where Dimensions CM performs all file operations such as check in and check out. All operations are relative to the folder that is referenced by your work area or project root folder. A work area can also be shared by a group of users.
A deployment area contains items that have reached a particular stage of development in the Global Stage Lifecycle. When items are promoted to a stage in the GSL you can also move them automatically to the deployment areas associated with that stage. For details about deployment, see the Dimensions CM online help.
A Library cache area contains copies of files whose items are located on a database on a remote server.