Network security is a critical domain within the broader field of cybersecurity, focusing on the protection of computer networks from various threats. It encompasses strategies, technologies, and policies designed to guard the integrity, confidentiality, and accessibility of data while in transit across network infrastructures. The core idea of network security is to protect large amounts of data using layered defenses that enforce rules before any action is allowed. These layers include physical network security, technical network security, and administrative network security.