This is a bit poorly worded so I apologise. I am asking about what people usually do to communicate with their classmates when they’re not in class: WhatsApp/iMessage groups with everyone in class, Snapchat groups, no big groups and you only have the numbers of your friends instead…
This question was inspired by something that just happened to me. I was talking to an English friend about me reaching out to an old classmate, and he expressed concerns about me stalking her to get her number. At every school I’ve gone to, in the first days of class, we made a big WhatsApp group chat with everyone’s numbers and that’s how I have everyone’s numbers. Apparently it is not the case in England