What is the primary purpose of a firewall in a network environment?

The primary purpose of a firewall in a network environment is to prevent unauthorized access. Firewalls serve as a barrier between a trusted internal network and untrusted external networks, such as the internet. They monitor incoming and outgoing traffic based on predefined security rules and policies. By allowing or blocking specific traffic, firewalls help protect sensitive data, maintain the integrity of network resources, and reduce the risk of cyber threats.

While firewalls can have some secondary effects, such as potentially enhancing network performance through traffic management, their fundamental role is security-oriented. Other options, like increasing internet speed or facilitating file sharing, do not align with the core function of a firewall, which is to safeguard the network from unauthorized access and potential attacks.