Instant chat is a type of communication service or online chat that enables two or more people to interact with one another in real time over the Internet through text messaging. It is also called instant messaging.
Some services allow voice messaging, file sharing, and video chat when both parties have cameras. Popular instant chat services include Yahoo! Messenger, MSN Messenger, AOL and Apple’s iChat.
Instant chat allows a two-way transmission of short messages between two parties. The message exchange on instant chat is near-instantaneous. If one party sends a message to a second party who is not online, the sender often receives a notification saying that the transmission cannot be completed or that the message is expected to be delivered when the user is available.