Hey dear ...here your answer.....

=> A computer network is a group of computer that are CONNECTED together and that COMMUNICATE with and sharing the resources (like printer , folder, etc ) from one to another.

■ Advantage
◆ resources and data security are controlled through the server (centralized).
◆ any or all element can be replaced INDIVIDUALLY as need increase (scalability).
◆ new TECHNOLOGY can be easily integrated into system (flexibility).
◆ all components (client / network / server ) work together (interoperability).
◆ server can be accessed remotely and across multiple platforms (accessibility).

■ Disadvantage
◆ when server goes down, operations will cease across the network (dependence).
◆ no central repository for files and applications (decentralized).
◆ does not PROVIDE the security available on a client / server network. (security).

♧ Note: these are some basic advantage and disadvantage basically advantage and disadvantage are based on what type of computer network it is. :)

...i hope its help...
...if any problem in understanding then you can ask in comment... ☆☆ :)