What is network security? Definition, methods, jobs & salaries
Network security is the practice of preventing and protecting against unauthorized intrusion into corporate networks. As a philosophy, it complements endpoint security, which focuses on individual devices; network security instead focuses on how those devices interact, and on the connective tissue between them.
The venerable SANS Institute takes the definition of network security a bit farther:
Network security is the process of taking physical and software preventative measures to protect the underlying networking infrastructure from unauthorized access, misuse, malfunction, modification, destruction, or improper disclosure, thereby creating a secure platform for computers, users, and programs to perform their permitted critical functions within a secure environment.