What is the difference between a keystroke and an accelerator?
Mmmh… A keystroke is, well, the striking of a key on a keyboard You might use a chord of keystrokes to trigger an accelerator, but you’re not required. Typing text is a series of keystrokes. An accelerator is an action triggered by special keystrokes. At least, that’s the way I interpret the two words, semantically speaking.
The phrases “key binding”, “key mapping” and “key accelerator” are all used pretty much synonymously these days.
The phrase “key chord” is either mostly synonymous with the above or means something slightly different, depending on the context. (It means something slightly different in the context of a chorded keyboard.) Some people have also used the phrase “key chord” to refer specifically to multi-step key bindings like Ctrl+K, Ctrl+Right as distinct from single-step key bindings like Ctrl+S.
At least, that’s my observations from usage.
“Key Chord” technically means to hold down multiple keys at once, just like a chord on a piano or a chord keyboard.