Flashback

It suggests an interruption of the present by a shot or series of shots representing the past. Flash forward is the exact opposite.
energy wipe effect

A line that travels across the screen, ‘pushing off’ one images revealing another but in word form.
fade

eliminating images from normal brightness to a black screen. A fade in the opposite. Signifies the passing of time
dissolve/lap dissolve

The slow fading out of one shot and the gradual fading in of it’s successor, with a superimposition of images, usually at midpoint