There is a universal term, AFAIK it's just "pressure" or "force", same as keyboard switches, but makers don't advertise it yet - probably because most mice don't have much to shout about. Mechanical keyboards changed that playing field by specifically advertising activation force and levels of feedback.
It's about the switch that is inside, and a little about the button design. Omron switches are the typical "light touch gaming switches with feedback", but in Razer Imperators for example they have been going flat (no press/repeat presses). The cheaper switches are often more rigid or simply limp (may appear responsive but have no feedback, may go flat fast with high APM). The design affects how much and how long your finger rests on the button (static load), how big of an arc you need to click, how it suits your grip etc.
I like my Steelseries Sensei Raw after two Razers died on me (Deathadder with busted wheel, Imperator with flat Omron switch, I later found out both were features of the designs). So far no news of "features" or switch death in Steelseries, but Sensei is a new model.
The cheaper Steelseries Kana has much stiffer switches than the Sensei, do not recommend it. I ordered three mice and kept the one I liked most.
PS. This is why you always, ALWAYS compare first, then make the final decision.