Spacebar speed test, or keyboard spacebar click-per-second test, stands for keyboard spacebar
Click Per Second test. It can be a simple 10-second test. Press and release your spacebar as many times as possible before time runs out. There is no limit to how many rounds you can play. You can try pressing the spacebar halfway and gently tapping it fast with another finger. You don't even have to lift your finger off the button if you're gentle enough.