Video editing involves manipulating video footage to tell a story or convey information in a clear manner. It allows filmmakers to cut out unnecessary parts, rearrange scenes for better flow, and add effects like filters. The key principles of editing include using shots, transitions, pacing, and following rules like the 180-degree rule to avoid disorienting viewers. Common techniques are parallel editing to show simultaneous scenes, match cuts to smoothly transition between shots, and continuity to maintain logical consistency. Editing is crucial for storytelling and helping audiences understand the message.