Messenger may refer to any of the following:
1. An abbreviation used for Facebook Messenger.
2. Alternatively known as MSN Messenger and Windows Live Messenger, Messenger is a software program from Microsoft for Windows that allow a user to chat online (Internet) with other users. Messenger is similar to text messaging, but on a computer rather than a cell phone. Users can also video chat if both users have a webcam connected to their computers.
Users are added to a contact list, then can be placed in various user-defined groups for easier viewing and sorting. Permission from a user is required before they can be added to another user's contact list. In the picture below is an example of MSN Messenger, with the contacts list shown on the right and the current chat conversation shown on the left.