Instant messaging

Instant messaging (IM) is a form of real-time direct text-based communication between two or more people using personal computers or other devices, along with shared software clients. The user's text is conveyed over a network, such as the Internet. More advanced instant messaging software clients also allow enhanced modes of communication, such as live voice or video calling.

Instant messaging (IM) is a collection of technologies used for real-time text-based communication between two or more participants over the Internet, or other types of networks. Of importance is that online chat and instant messaging differs from other technologies such as e-mail due to the perceived synchronicity of the communications by the users –chat happens in real-time. Some systems permit messages to be sent to people not currently 'logged on' (offline messages), thus removing some of the differences between IM and e-mail (often done by sending the message to the associated e-mail account).

IM allows effective and efficient communication, allowing immediate receipt of acknowledgment or reply. In many cases instant messaging includes additional features which can make it even more popular. For example, users can see each other by using webcams, or talk directly for free over the Internet using a microphone and headphones or loudspeakers. Many client programs allow file transfers as well, although they are typically limited in the permissible file-size.

It is typically possible to save a text conversation for later reference. Instant messages are often logged in a local message history, making it similar to the persistent nature of e-mails.