Professional Security Institute Practice Exam

The primary function of firewalls in network security is to control incoming and outgoing network traffic based on predetermined security rules. This involves monitoring and filtering data packets that attempt to enter or exit a network. Firewalls create a barrier between trusted internal networks and untrusted external networks, enabling organizations to protect sensitive data and resources from unauthorized access and potential threats.

By applying specific rules regarding which traffic is allowed or denied, firewalls help manage the flow of information and ensure that only legitimate communication is permitted. This functionality is essential for maintaining network integrity, confidentiality, and availability, as it can help prevent various types of cyber threats, including intrusions and attacks.

Other options provided do not accurately describe the primary role of a firewall. For instance, encrypting sensitive data during transmission is typically the role of protocols or encryption technologies, while secure data storage usually involves solutions like backup systems and cloud storage. Detecting and removing malware is mainly the function of antivirus or antimalware programs rather than firewalls. The unique ability of firewalls to define network traffic rules distinguishes their primary function in the realm of network security.