Computer Assisted Notetaking means using a computer to type on a normal computer (QWERTY) keyboard to display what is said in a meeting or verbal exchange.
It may be as simple as having someone who can hear and type fast act as a notetaker for your meeting, but depending on the skill of the typist, a lot may have to be glossed over. It's very difficult to accurately and completely transcribe spoken words in real time with a QWERTY keyboard.
There are professional CAN operators who not only are very skilled at typing in near real time, but who use special software and pre-trained codes to improve their accuracy and speed.
CAN support of a meeting typically requires one or more CAN operators to be present in the meeting room. One operator is sufficient if the meeting is short, but longer meetings require at least two operators so they can alternate after 20-30 minutes of this extremely exhausting work.
It's also possible to use "Remote" CAN operators. To do this, you need a way to get the audio of the meeting transmitted, live, to the CAN operator (who may be hundreds of miles away), and a way to get the typed text sent back to the meeting room (again, live) and displayed.