What are “lots of people”? 10? 250? And the chat is the meeting? Or is the tool and chat just there to schedule a meeting, which is the to take place elsewhere

What are “lots of people”? 10? 250? And the chat is the meeting? Or is the tool and chat just there to schedule a meeting, which is the to take place elsewhere (in real life, on Zoom, or whatever)? Does the group of people change each time? Does it have to work on mobile?