Client/Server (Client-server) - A way to distribute data on a network to a number of computerized devices such as set-top boxes and/or PCs.  The server (also known as “host”) stores and maintains the data. It provides the "client" computerized devices access to this data when the client devices request it. The Internet is largely based on this as well as video on demand.

Client-server architectures are sometimes called “Two-tier”.

Client side vs. Network side