POP3 and IMAP are two different protocols (methods) used to access email. Each has its own advantages.
POP3 downloads email from a server to a single computer, then deletes it from the server. So POP3 is most useful if you want to keep all your email on one computer and check emails only on that computer, and not from any other device.
IMAP is the better option - and the recommended option - when you need to check your emails from multiple devices, such as a work laptop, a home computer, or a tablet, smartphone, or other mobile device. Tap into your synced (updated) account from any device with IMAP.
Here are the differences between POP3 and IMAP.
|POP3 - Post Office Protocol||IMAP - Internet Messaging Access Protocol|
|You can use only one computer to check your email (no other devices)||You can use multiple computers and devices to check your email|
|Your mails are stored on the computer that you use||Your mails are stored on the server|
|Sent mail is stored locally on your PC, not on a mail server||Sent mail stays on the server so you can see it from any device.|