When working in a collaborative environment, you can check out and check in files when transferring them between a remote server and your local computer. When a file is checked out, Dreamweaver displays a check mark over the file's icon in the Site window. A green check mark indicates that the file was checked out by you, and a red check mark indicates that the file was checked out by another team member. The name of the person who checked out the file is also displayed in the Site window. You can only check in files that you've checked out.

Checking in a file makes the file available to other team members to edit, but also makes the local version a read-only file to ensure that you don't accidentally edit a checked-in file.

Dreamweaver keeps track of checked out files by placing a text file (with the extension .lck) on the remote server, which includes the name of the user who checked out the file, the date, and the time. The .lck files are not visible in the Site window.

Dreamweaver does not make checked-out files read-only on the remote server. If you transfer files with an application other than Dreamweaver, you can overwrite checked-out files. The .lck file is visible next to the locked file in the file hierarchy, and when opened, indicates that the file is currently being edited by another team member.