What is the main function of a firewall in a network?

The main function of a firewall in a network is to filter and control incoming and outgoing network traffic. A firewall acts as a security barrier between a trusted internal network and untrusted external networks, such as the internet. It uses predefined rules to permit or deny data packets based on security settings, helping to protect the network from unauthorized access, cyber threats, and harmful traffic. By doing so, firewalls play a crucial role in maintaining the integrity, confidentiality, and availability of network resources.

While enhancing network speed and monitoring performance are beneficial aspects of network management, they are not primary functions of a firewall. Similarly, although user authentication may be a part of broader security policies, it is typically managed by different systems or protocols rather than the firewall itself. Thus, the filtering and controlling of network traffic is what distinctly defines the purpose of a firewall.