n. (context communication computing English) A form of realtime communication where two or more people exchange text messages, usually short, using computers or other devices with communications capabilities.
Instant messaging (IM) is a type of online chat which offers real-time text transmission over the Internet. A LAN messenger operates in a similar way over a local area network. Short messages are typically transmitted bi-directionally between two parties, when each user chooses to complete a thought and select "send". Some IM applications can use push technology to provide real-time text, which transmits messages character by character, as they are composed. More advanced instant messaging can add file transfer, clickable hyperlinks, Voice over IP, or video chat.
Non-IM types of chat include multicast transmission, usually referred to as "chat rooms", where participants might be anonymous or might be previously known to each other (for example collaborators on a project that is using chat to facilitate communication). Instant messaging systems tend to facilitate connections between specified known users (often using a contact list also known as a "buddy list" or "friend list"). Depending on the IM protocol, the technical architecture can be peer-to-peer (direct point-to-point transmission) or client-server (a central server retransmits messages from the sender to the communication device).
Usage examples of "instant messaging".
I decided to try instant messaging Michael, telling him I really needed to talk to Lilly and would he please go off-line so I could call her.
She was thankful she'd found him on this early in the evening and glad she'd exchanged instant messaging information with at least some of the chat group.
AOL had just shot past 15 million subscribers and was gobbling up CompuServe and ICQ, pioneers of instant messaging.
We don't exchange Christmas cards or share instant messaging, and he's totally out of my Rolodex.