The Review tab contains all of the commands you need when reviewing your document before finalizing such as Proofing, Comments and Changes.
Figure 1. Review Tab
In the Proofing group, you’ll find commands for running the spell check utility and the thesaurus for when you’re looking for that perfect synonym.
Figure 2. Proofing Group
The Comments group was desired to take care of all of your commenting needs from inserting a new comment to deleting existing comments and everything in between. For those of you coming from previous versions of Excel, all of the Shortcut Menu commands for working with comments remain the same.
Figure 3. Comments Group
Finally, in the Changes group, you’ll find all you need for protecting your worksheets and workbooks as well setting your workbooks up for sharing with others.
Figure 4. Changes Group