Let's first understand what network security is. Network security is an activity intended to secure the integrity and usability of one's network and data. It includes a set of policies to prevent and monitor unauthorized access of network resources.
Network security covers a different set of public (internet) and private (local) network, which is used for the transfer of data between business organizations, government agencies, security organizations, and so on.
We could say that it's a set of policies that secure all the data transmission that happens over the network and network resources as well. When we use the network resource, it means all the nodes are connected together through the communication channel to transfer data and information.
Now, the question is, how does it work? Network security defines multiple layers of security...