IMAP is not an email provider, it's just another protocol for reading your mail. It is the successor of POP3, having several key improvements. Somewhat like HTTP2 is to HTTP.
If both your email provider and your client (aka mail reading software) support it, there really is no reason to use POP instead of IMAP.
If both your email provider and your client (aka mail reading software) support it, there really is no reason to use POP instead of IMAP.