No, not that type of action. What piano people mean when they say “action”.
Yeah, it’s a little different than the other definitions you may be familiar with. When piano people say “action” they are referring to the mechanisms that engage and operate when one’s hands press the keys on the piano’s keyboard. One might hear the terms “light”, or “heavy” or “sluggish” in regards to this term. And just like piano tone, there exists different preferences amongst pianists. The piano action can be adjusted by altering weights in the keys, or by adjusting one or more of the many parts involved in projecting the hammers toward the strings. These adjustments are called “action regulation” and should be performed in relation to the amount of use, or to alter the feel to the owner’s taste.