Network access control is a loom towards computer network security system. Network access control uses set of rules that commands the communication within the network. These rules or protocols define the implementation of policies. In network access control, these policies depict how to make safe admittance to the network nodes by devices.
In simple language, as name suggests, network access control is a policy that restricts access to network, as all computers that are connected to the network are not allowed to perform any task without permission. In network access control, a computer is allowed to access the network assets and the internet only when the policy needs are satisfied.