Either way, these programs require a user to log on and use a designated username (screenname / handle etc.) that becomes their identity on the system while in use.
Instant Messaging (IM or IMing) is a service allowing users to send typed messages, pictures, files, and live video to a recipient based on their screen name.
This exchange can go back and forth as long as both parties desire.
You can change this preference in your Second Life dashboard or the Viewer.
On the Web: As a member of a group, you can send IMs to everyone in the group.
The program handles all the communication and provides a window for the user to type and receive messages. offer messaging as part of the overall platform it offers customers along with many other options.
Additionally, companies like Alphabet (Google), Microsoft, and Yahoo offer membership accounts allowing users to register in exchange for access to web services like e-mail, office programs, document storage, calendar, messaging, and many other resources for free.
There are several available with some of the more popular ones being Whats App, Facebook Messenger, QQ Mobile, We Chat, Viber, and even Skype.
The old days it was Yahoo Messenger, Windows Live Messenger, and AIM (America Online IM).
It provides a personal way of communicating with friends and other known contacts and is very popular among teenagers as well as many adults.