Review tab in Excel :- Click the Review tab in Excel and you will find buttons related to proof reading your Excel worksheet, tracking changes, working in other languages and protecting Excel worksheet or workbook.

There are four groups in Review tab in Excel :
- Proofing Group
- Language Group
- Comments Group
- Changes Group
Proofing Group
Proofing tools are used to do research with data like Spelling, Checking, Thesaurus, Translate etc.

Spelling (F7)
Spelling is the vital tool of Excel which is used to check and correct spellings as well as Grammatical mistakes.
Research (Alt+Click)
Research is the tool which is used to do investigate or comparison or find meaning of a specific word in different language and scenario with all references books and assistance. In default, there are few English standards set like English (US), English (UK), French Spanish, Arabic etc.
Treasures
Thesaurus is the Dictionary or vocabulary of word with different language set. We can formally call it as vocabulary which is used by the Research tools to investigate or find the meaning of the word.
Language Group

Translate
This command is used to find the translation of a specific word in different language. There are some languages standards set to do the translation into. This also used by the Research tool which does monitoring of the words doing whether Translation or finding thesaurus.
Comments Group
This group of tools put Comments to a particular section or Page area and Navigating with them as well.

New Comment (Shift+F2)
By using this option, we can add a note about this part of the document.
Delete
By using this option, we can delete a selected comment.
Previous
By using this option, we can go to the previous comment.
Next
By using this option, we can go to the next comment.
Show/ Hide Comment
By using this option, we can show or hide the comment on the active cell.
Show All Comments
By using this option, we can show all the comments in the worksheet.
Show Ink
By using this option, we can show or hide ink on the sheet.
Changes Group
This group of tools as per the name changes few attributes of the worksheet like Protection, Sharing, Track changing and many more.

Protect Sheet
By using this option, we can prevent unwanted changes from others by limiting their ability to edit. For example, you can prevent people from editing locked cell or making formatting changes.
To protect the sheet follow these steps:
- Under Review tab, click Changes group and then click Protect Sheet.
- Here, In Allow all user of this worksheet to: list box, select the elements that you want users to be able to change.
- If you prefer, enter a password in the Password to unprotect sheet: text box.
- Click OK.
Protect Workbook
By using this option, we can keep others from making structural changes to our workbook, such as moving, deleting or adding sheets.
To protect the workbook follow these steps:
- Under Review tab in Excel, click Changes group and then click Protect Sheet.
- In the dialog box, click on the Structure: check box if you want to protect the structure.
- Click on Windows: check box if you want to keep workbook windows in the same size and position each can you open the workbook.
- If you prefer enter a password in the Password: text box.
- Click OK.
Share Workbook
By using this option, we can share our workbook so that others can work in it at the same time.
Protect and Share Workbook
By using this option, we can share our workbook and protect change tracking with a password.
Allow Users to Edit Ranges
By using this option, you can setup password protection on ranges and choose people who can edit those ranges. Once setup, click protect sheet to activate the password protected ranges.
Track Changes
By using this option, we can keep track of changes made to this document. This is especially useful when the document is almost done and you are working with others to make revision or give feedback.