Jump buffering
Also said as Input buffer, Early jump
The game remembers a jump pressed just before landing and performs it on the first frame you touch the ground.
Nobody can hit a one-frame window on purpose, again and again. Without a buffer, chained jumps feel as if the button sometimes ignores you.
Say it
“Buffer jump presses for 120 ms before landing, so a chain of jumps never drops an input.”
Where you’ve seen it
Celeste buffers the jump, so pressing just before landing makes you jump on the exact frame you land.
Not to be confused with coyote time
Buffering forgives a press that came too early. Coyote time forgives one that came too late.