A firewall is a network security device or software application 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 untrusted external networks, such as the internet, to prevent unauthorized access, data breaches, or malicious activities. Firewalls can be implemented in hardware, software, or a combination of both, and they analyze network packets to determine whether to allow or block traffic based on criteria such as IP addresses, ports, protocols, or specific types of content. By enforcing security policies, firewalls help protect computer systems, networks, and data from various cyber threats, including malware, hackers, and unauthorized access attempts.
