Reading some user manuals in German, I sometimes encounter the word Taste and sometimes Taster. Is there any difference to a native German speaker?
There actually is a difference:
Taste can be used for more or less anything that is operated by a finger press, e.g
- Piano key
- (mechanical) typewriter key
- key connected to a momentary electrical switch (on a computer keyboard, for example)
while Taster works for the momentary electrical switch only and is typically used for single switches (while the switches inside your computer keyboard might be single "Taster" in an electrical sense, the keys are referred to as "Tasten" in their mechanical sense).
So even if the two words are very similar, Taste would normally translate to "key" in English, while Taster typically translates to "(momentary) switch"
Those were the translations in terms of day-to-day usage. Translations for Taster can differ on whether the word is used as a technical term in mechanical or electrical context - Taster is also often used in mechanical engineering for instruments that "feel" a specific measure - Innentaster is the German technical term for "inside caliper".