Game speed and background logic is synced with drawn frames, meaning the actual game slows down or speeds up depending how fast it gets rendered and not just getting choppier or more fluid graphics. Top speed may be limited (via VSync or FPS cap).
Alternate name: Frame synced logic
The first video game about Frame synced was released in 1982.
For single player games this has little meaning most of the time, but for multiplayer games this means the framerate drops for all players if even one player's machine can't keep up with the graphics or the background AI calculations.
Normally games would graphic-wise run fast for everyone but only the background logic would slow down, with frame synced the framerate drops with the background logic slowdown (not that rendering the slowed logic as fast as before has any real benefits). However, this also creates unnecessary slowdown for other people if the rendering itself is too slow for one person and not the background logic (that one person whose rendering is slow could skip frames instead of forcing rendering them).
It's a very rigid and simplistic way to do things not exactly suitable for multiplayer, usually limited to single threaded games that calculate logic, input, game events and whatever else, and then draws a frame, waits few moments if there's time (to keep a steady framerate), and repeats the process, skipping nothing. The only change is the duration of that wait period.
* NOT for games where the background logic skips "frames" when framerate drops (e.g. games using quake engine). The only thing shared with these two is that the background logic is heavily tied into the graphics logic.
* NOT for games that v-sync. This is syncing with logic, not display refresh rate.