How IMAP and POP differ.

IMAP (Internet Message Access Protocol) is a newer protocol that allows you to remotely access and manage your email. What you do in the app affects email on the email server.
•2-way sync - Emails stay on the server and are accessed remotely.
•Full access - Access every email from every folder using the app.
•Record of sent email - Email you send using the app is saved on the server.
•Manage mailbox once - Emails deleted or moved in the app are deleted or moved on the server.

POP (Post Office Protocol) is an older protocol that copies emails from the email server to the app. Actions performed in the app don't affect email on the email server.
•1-way sync - Only downloads email from the server.
•Limited access - Only download emails from the Inbox.
•No record of sent email - Emails sent from the app are not saved on the server.
•Manage Inboxes independently - Deleting or moving email in the app isn't reflected on the server.
•Keep email on server options - Different settings allow you to leave a copy of your email on the server, or delete it when it's downloaded.