What Does Check-in/Check-out Mean?

Check-in and check-out are common terms in many document management systems, including SharePoint. Their purpose is to prevent conflicts in an environment where multiple people might want to edit the same piece of content (in SharePoint, list items or files) at the same time. The term check-in describes the process of adding a new or modified item or file to a document library or a list to replace the previous version. The term check-out describes the process of getting a version of a document or list item in a list or library. By checking out an item or a file, a user can prevent others from editing that content. By checking in the item, the user can allow others to edit the content, without needing to worry about overriding changes that others have made.

Usually when an item or a file is checked out to a user, that user can work on that item or file, and other users cannot. Other users must wait for the user to check in the item or file again (that is, perform a check-in) before they can edit the item or file. While the item or file is checked out, other users usually can see only the last version that was checked in; they can't see the changes that the current user has made on the file while it's been checked out.

Pages in SharePoint can be in document libraries—and often are. This means that pages can be checked out and in, allowing page editors to change a page (for example, add or remove a web part), but the users cannot see the changes until that editor is happy with the changes and checks in the page.