Email means Electronic Mail, which is a method of exchanging messages between people using electronic devices. Email first entered limited use in the 1960s and by the mid-1970s had taken the form now recognized as email.
Email operates across computer networks, which today is primarily the Internet. Today's email systems are based on a store-and-forward model. Email servers accept, forward, deliver, and store messages. Neither the users nor their computers are required to be online simultaneously; they need to connect only briefly, typically to a mail server or a webmail interface, for as long as it takes to send or receive messages.