Explanation:

Chatting- Internet at the same time you are. Usually, this "talking" is the exchange of typed-in messages requiring one site as the repository for the messages (or "chat site") and a group of users who take part from anywhere on the Internet.

Social Networking- the use of dedicated websites and applications to interact with other users, or to find people with similar interests to one's own.

Modem- a piece of equipment that connects two or more computers together by means of a telephone line so that information can go from one to the other