The purpose of a firewall is to protect a computer or network by monitoring and controlling 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 and cyber threats
. Key functions of a firewall include:
- Inspecting and authenticating data packets to allow only legitimate traffic to pass through, thereby blocking malicious or unwanted traffic
- Preventing unauthorized users, such as hackers, from accessing private networks or sensitive data
- Filtering traffic according to rules that can restrict access to certain websites or applications, useful for parental controls or workplace restrictions
- Providing a first line of defense against cyberattacks, including blocking threats like viruses, worms, Trojans, and denial-of-service attacks
- Managing network resources and sometimes offering additional services like VPN support to secure communications
While firewalls are essential for network security, they do not protect against all threats, such as malware introduced through email links or insider attacks that bypass the firewall
. In summary, a firewall's primary purpose is to secure networks by allowing safe traffic in and out while blocking unauthorized or harmful traffic, thus reducing the risk of cyberattacks and unauthorized access
