What is a firewall generally used for?

A firewall is primarily used for protecting internal networks from external threats. Its main function is to monitor and control incoming and outgoing network traffic based on predetermined security rules. Firewalls act as a barrier between a trusted internal network and untrusted external networks, such as the internet. By filtering traffic, firewalls help ensure that only authorized data packets can enter or exit the network, thereby safeguarding sensitive information and preventing unauthorized access or attacks from malicious entities.

While separating internal networks from unsecured devices and controlling access are also important aspects of network security, the core purpose of a firewall is focused on defense against external threats. Its primary role is to bolster the security posture of internal networks, reducing the risk of attacks and breaches that could compromise data integrity, confidentiality, and system availability.