Which one among the following is the purpose of firewall ?

A firewall is a critical network security device or software designed to monitor and control incoming and outgoing network traffic based on predetermined security rules. Its primary purpose is to act as a barrier between a trusted internal network and untrusted external networks, such as the internet, to prevent unauthorized access. By filtering data packets based on factors like IP addresses and protocols, it ensures that only legitimate communication is allowed while malicious traffic is blocked. While antivirus software focuses on scanning and deleting harmful files or viruses already on a system, a firewall serves as the first line of defense by regulating the flow of data at the network perimeter. Therefore, the fundamental role of a firewall is to safeguard digital assets from unauthorized external intrusion.