Cyber security refers to protecting computers, networks, programs, and data from unauthorized access or attacks. It involves techniques to defend hardware, software, electronic data, and the services computers provide from theft, damage, or disruption. Viruses are harmful programs that install themselves on computers without permission. To improve cyber security, individuals should use updated software and antivirus programs, strong passwords, and avoid suspicious emails and links while backing up important data. Organizations should train staff to be cyber aware and manage security with suppliers and partners.