How to Use Track Changes Feature in Word 2013

In cases where there are multiple users are working on the same document, remotely, there are various challenges that require attention. Firstly, there must be a way to identify each user and the changes they make so that other users don’t get caught in confusion due to run-time editing. Secondly, the original document and the structure must remain intact in order to approve or enhance the changes made by a user. This would inherently highlight the need for user as well as document administration. Once you enable the track changes feature in Microsoft Word 2013 by selecting the Review tab in the ribbon interface and clicking the Track Changes button (it should turn blue as soon as you click it, indicating that the feature has been successfully enabled).

http://www.writeawriting.com/ms-office/how-to-track-changes-microsoft-word-2013-guide/