Computer and network surveillance means that someone is watching what you do on your computer or looking at what you do on the internet. It might be your parents keeping track of what websites you visit, or your employer monitoring your emails and chats. It could also be the government looking through your computer or tracking your internet use to make sure that you are not doing anything dangerous or illegal. No matter who is doing it, they can see what kind of websites you visit, what kind of emails you send, and even what kind of photos you share with your friends. It's like someone looking through a window and seeing what you do on the other side.