Other forms: keystrokes
A keystroke is the tap of a letter, number, symbol, or command on a computer keyboard. It takes ten keystrokes to type the word vocabulary.
The noun keystroke wasn't common until after the invention of computers, although you can use it when you talk about pressing a key on a typewriter as well. Online stores have made it dangerously easy to buy things, sometimes with only a few keystrokes. The word comes from the sense of stroke that's defined as "act of striking."