Deepfake is a portmanteau created by combining the terms "deep learning," which is an artificial intelligence term, and "fake." A deepfake is a fictitious video or image generated by compositing information from multiple sources. As the name suggests, deepfakes are created by advanced artificial intelligence programs that analyze reference footage to create realistic simulations.
Most popular deepfake videos consist of a recognizable public figure or celebrity, who is combined with footage of someone else to deliver a fake message. A deepfake is created by letting a computer analyze a large selection of facial footage movements and behaviors of the subject, and with AI attempting to replicate them over the new footage.