Dissolve

Also called a cross dissolve or a crossfade. Editing convention reads it as time passing or place changing, which is why it feels right between scenes and wrong between two angles of the same conversation. Duration carries meaning on its own: a few frames is close to a soft cut, a second or more announces itself. It is the default transition in every editing application and comfortably the most overused one, largely because it is the easiest button to reach. Hard cuts should carry most of a video, with a dissolve held back for the moments where the jump in time or place is the actual point.