In a hierarchical network, one or more computers is more powerful than the rest. The relationship between the nodes is called a client–server relationship. The more powerful server, (or servers), looks after printing, file maintenance and other peripherals.
Less powerful computers called clients are connected to the network.
The clients may have no disk drives nor processing power of their own.
They make use of the functions provided by the server.
Where a file server is a dedicated file server, it cannot be used as a terminal and will be occupied all the time in managing the network.
There are two types of server, the file server and the print server. The file server is used to store both programs and data. It acts as a massive hard drive on behalf of all the client terminals.