Comment: -It is used to input the message in selected cells which display when the move mouse pointer in it.
Process: -
ü Select your cell
ü Click on review tab
ü Click on comment
ü Input the message
Protect sheet: -It is a part of protection which used to protect of active sheet. After using of this feature your sheet will make read only.
Process: -
ü Click on review tab
ü Click on protect sheet
ü Enter password and ok
ü Again enter password and click on ok
Protect workbook: -It is a part of protection also which provide to lock the worksheet, windows etc.
Process: -
ü Click on review tab
ü Click on protect workbook
ü Click protect structure and windows
ü Check windows option
ü Enter password and ok
Again enter password and click on ok