A computer network is a set of computers sharing resources located on or provided by network nodes. Computers use common communication protocols over digital interconnections to communicate with each other. These interconnections are made up of telecommunication network technologies based on physically wired, optical, and wireless radio-frequency methods that may be arranged in a variety of network topologies.

Cisco Certified Network Associate

The CCNA—which stands for Cisco Certified Network Associate—is an entry-level information technology (IT) certification issued by networking hardware company Cisco.