Võrgutulemüür

Võrgutulemüür, commonly known as a firewall, is a network security device or software that monitors and controls incoming and outgoing network traffic based on predetermined security rules. It acts as a barrier between a trusted internal network and an untrusted external network, such as the internet. The primary function of a firewall is to prevent unauthorized access to or from a private network.

Firewalls can be implemented in various forms. Hardware firewalls are physical devices placed at the network perimeter, while software firewalls are applications installed on individual computers. They operate by examining data packets and comparing them against a set of defined rules. These rules can be based on various criteria, including IP addresses, ports, protocols, and even application types.

The effectiveness of a firewall lies in its ability to enforce security policies. It can block malicious traffic, prevent unauthorized connections, and log network activity for auditing purposes. By filtering unwanted or potentially harmful data, firewalls help protect networks and the sensitive information they contain from cyber threats like viruses, malware, and intrusion attempts. Regular updates and proper configuration are crucial for maintaining the security posture provided by a firewall.