What is the purpose of a host firewall?

A host firewall is designed to act as a barrier between a trusted internal network and potentially untrusted external networks, such as the internet. Its primary purpose is to monitor and control incoming and outgoing network traffic based on predetermined security rules. By filtering this traffic, a host firewall helps prevent unauthorized access to the computer or network it protects, effectively defending against various network-based attacks, such as those involving malware, spyware, or hackers attempting to breach security protocols.

The other options do not align with the primary function of a host firewall. Speeding up internet connections pertains more to bandwidth management or network optimization techniques rather than security. Encrypting data transmissions involves securing data to prevent eavesdropping, which is typically handled by different technologies, such as VPNs or encryption protocols, not firewalls. Managing software updates is a separate task generally performed by operating systems or specific software management tools, not by firewalls themselves. Thus, the primary focus of a host firewall is clearly to provide protection against network-based attacks, making that the correct answer.