Loading screen
Also said as Load time, Loading tips, Playable loading screen
What the player sees while the game reads what it needs from the disc or drive. It can be a blank screen, a progress bar, a tip or even a bit of play.
A wait with nothing happening seems longer than the same wait with something to look at, and a black screen can't be told apart from a crash. The time itself matters most, since people quit over it, but showing progress is cheap and it always helps.
Say it
“Show a real progress bar that never goes backwards, and let the player keep practising combos on a dummy while it loads. Keep tips to one line.”
Where you’ve seen it
Ridge Racer on the first PlayStation let you play Galaxian while the main game loaded. Namco patented the idea of games during loading screens, and that patent only expired in 2015. Bayonetta keeps you playing with its own moves during loads.
Not to be confused with friction
Loading is a wait the machine imposes. Friction is any cost, including ones you could remove with a redesign tomorrow.