Connectivity is how well computers and other electronic things can join up with other computers, networks, or programs — whether they can talk to each other at all, and how smoothly. People use it for phones, wifi, Bluetooth, and office systems: poor connectivity means the signal drops, the app cannot reach the server, or devices will not pair. It names the ability or the quality, not the cable in your hand and not one single joining. A shop might advertise “better connectivity”; a technician might check “network connectivity.” People do stretch it. You will also hear it for transport (how well places are linked) and, more loosely, for people staying in touch. The computer sense is the one you will meet first in learner English. It is a slightly technical, modern noun — at home, many people just say the wifi is bad.

連線能力、連接性（台灣講電腦、網路時也常直接說「連線」）