What is the purpose of firewalls in network security?

Firewalls serve a crucial role in network security by monitoring and controlling incoming and outgoing network traffic based on predetermined security rules. Their primary purpose is to establish a barrier between a trusted internal network and untrusted external networks, such as the internet. By enforcing these rules, firewalls can block or allow traffic to specific ports or IP addresses, helping to protect the network from unauthorized access, cyber threats, and data breaches.

In practice, firewalls can operate at various levels, including application, transport, and network layers, making them versatile tools for security management. By understanding and implementing the appropriate rules, organizations can ensure that only authorized traffic is permitted, thereby maintaining the integrity and security of their networked systems. This functionality is fundamental to an organization's overall cybersecurity strategy, allowing it to mitigate potential threats effectively.