What are the advantages of IMAP over POP?

The major advantage is that, IMAP shows you a copy of the email you receive unlike POP where the email you receive is being downloaded to your computer first and deleting the copy on the server.(POP is usually being used in stand-alone email client software like Thunderbird) So you see, if accidentally something terrific happens to your computer and you will have no option other than formatting and reinstalling your Operating System, you will loose the emails. But the stand-alone email clients will ask whether you want to download only a copy of the emails you receive preserving the original mail on the server.