Cyber security is a subset of information security which refers to a set of techniques and methodologies used to protect integrity of networks, devices, programs, and data from damage, attack, or unauthorized access. In simple terms, cyber security is the practice of protecting internet-connected systems and networks from digital attacks. Network security, on the other hand, is the act of protecting files and directories in a network of computers against misuse, hacking, and unauthorized access to the system. Network security is a subset of cyber security which protects the integrity of your network and network-accessible resources from unauthorized access. You can refer the following image as well.