Backchannel is the practice of using networked computers to maintain a real-time online conversation alongside live spoken remarks. The term was coined in the field of Linguistics to describe listeners' behaviours during verbal communication, Victor Yngve 1970.

The term "backchannel" generally refers to online conversation about the topic or the speaker. Occasionally backchannel provides audience members a chance to fact-check the presentation.

First growing in popularity at technology conferences, backchannel is increasingly a factor in education where WiFi connections and laptop computers allow students to use ordinary chat like IRC or AIM to actively communicate during class. More recently, researchers from Penn State University have explored bringing "backchannel" up front in classrooms using what they call "ClassCommons," to increase students' participation in large size classes.

Twitter is also widely used today by audiences to create backchannels at technology conferences. When audience members add an event hashtag to their tweets (for example, #w2e was the hashtag used for the Web 2.0 Expo New York in 2009), anyone can run a Twitter search to review all the backchannel tweets related to that event.