IMAP stands for Internet Message Access Protocol and is a protocol used to access emails via an email client on a remote server.
IMAP is suited for people who want to receive e-mail on more than one device, which nowadays is most people who carry a smartphone. IMAP stores e-mail on remote servers – rather than downloading them to local storage – which is how the e-mails can be viewed on different devices. When your read, download or make any changes to e-mails on one device, it will synchronise across any other device using the same account. IMAP has the ability to only download the header of an e-mail so it can also be much quicker.