What does a firewall primarily do?

A firewall primarily functions to restrict unauthorized access to or from a private network. It serves as a barrier between a trusted internal network and untrusted external networks such as the internet. Firewalls enforce a set of predefined security rules that determine which incoming and outgoing traffic is allowed or denied. This helps protect sensitive information and maintain the integrity of data within the network.

For instance, by blocking unwanted or suspicious traffic, a firewall helps prevent attacks such as hacking or malware infections. It can also enable administrators to set up specific access controls to further secure the network.

While options like encrypting data, backing up data, and monitoring user activity are important aspects of cybersecurity, they do not specifically describe the primary role of a firewall. Encryption is focused on protecting data integrity by converting it into a secure format, backing up data relates to making copies of data for recovery purposes, and monitoring user activity is about tracking actions taken by users on a network. Each of these functions has its role, but the main purpose of a firewall centers on controlling access to the network to enhance security.