Comparing and Merging Documents
If you want to compare an earlier version of a document with the current version, or if you receive multiple edited versions of the original document back from the recipients, you can compare the documents and merge the changes into one document. The changes can be merged into one document or viewed for comparison. When you compare or merge documents, the text that differs between the two versions will be highlighted in a different color or with track reviewing marks.
Click the Review tab.