It encompasses a wide range of policies, processes, and technologies designed to safeguard the integrity, confidentiality, and accessibility of computer networks and data. 

• Types of Threats: Network security aims to protect against various types of threats including viruses, worms, spyware, malware, ransomware, phishing attacks, and hacking attempts.

• Layers of Defense: Effective network security involves multiple layers of defense at the edge and in the network. Each network security layer implements policies and controls to safeguard users' data.

• Firewalls: A firewall is a fundamental component of network security, acting as a barrier between a trusted network and an untrusted network. It controls incoming and outgoing network traffic based on predetermined security rules.

• Virtual Private Networks (VPNs): VPNs provide secure remote access to a network, encrypting data transmitted over public networks.

• Access Control: Properly controlling who has access to network resources is vital. This includes implementing user authentication, permissions, and policies to ensure that only authorized users can access and modify data.

Network security is not only about preventing attacks but also about being able to quickly detect and respond to them. In today’s digital age, the importance of network security cannot be overstated, given the frequency and sophistication of cyberattacks.