There are only two levels and the operations are carried out entirely on the server. As an example, we can mention the classic static or dynamic websites. The tools for the realization of these types of applications are the network sockets, whose programming is possible in various languages, including C, C ++, Java, and, of course, Python.

The term client-server system refers to a network architecture in which a client computer or client terminal is generally connected to a server for the use of a certain service; for example, the sharing of a certain hardware/software resource with other clients, or relying on the underlying protocol architecture.