What is a Firewall in Computer Network?

A firewall in a computer network is a security system that monitors and controls incoming and outgoing network traffic based on predetermined security rules. Essentially, it acts as a barrier between a trusted internal network and untrusted external networks, such as the internet. A firewall can be hardware, software, or a combination of both. Its primary purpose is to prevent unauthorized access to or from a private network. By inspecting network traffic, it can block or allow data packets based on specific security criteria, ensuring that only legitimate traffic is allowed through. Firewalls are crucial for protecting network security, preventing unauthorized access, and stopping malicious software and attackers from gaining access to sensitive data.