What is the main purpose of a firewall?

The main purpose of a firewall is to control network traffic based on security rules. Firewalls act as barriers between trusted internal networks and untrusted external networks, such as the internet. They monitor and filter incoming and outgoing traffic according to predetermined security protocols. By setting specific rules, firewalls can block or allow data packets, helping to protect internal systems from unauthorized access, cyberattacks, and data breaches.

This functionality is crucial in maintaining network security and ensuring that only legitimate traffic can enter or leave the network, thereby safeguarding sensitive information and resources from potential threats. Firewalls can operate at various levels of a network, including software-based and hardware-based solutions, reinforcing their role as a foundational element in an organization's security infrastructure.