What is the purpose of a firewall in network security?

The purpose of a firewall in network security is to prevent unauthorized access to or from a network. Firewalls serve as a barrier between a trusted internal network and untrusted external networks, such as the internet. By monitoring and controlling incoming and outgoing network traffic based on predetermined security rules, firewalls can block malicious traffic, unauthorized users, and potential threats before they reach sensitive data or network resources.

This critical function contributes to the overall security posture of an organization, ensuring that only authorized communications are allowed while blocking potentially harmful interactions. Other options, while related to network management, do not align with the core function of a firewall: improving network speed, storing data securely, and managing email accounts do not address the fundamental role of firewalls in maintaining security.