What is the main objective of a firewall in network security?

The primary objective of a firewall in network security is to prevent unauthorized access to or from a network. Firewalls act as a barrier between a trusted internal network and untrusted external networks, such as the internet. They achieve this by filtering incoming and outgoing traffic based on predetermined security rules, effectively controlling which data packets are allowed through.

By ensuring that only authorized users and devices can access the network, firewalls protect against various threats, including hackers and malicious software trying to exploit vulnerabilities. This foundational aspect of network security helps maintain the integrity, confidentiality, and availability of sensitive information within the network, making it a key element in safeguarding an organization’s digital assets.

The other options address different aspects of network and data management: detecting malicious software focuses on threat detection rather than prevention of unauthorized access, increasing network speed and efficiency pertains more to network performance than security, and backing up data securely relates to data protection rather than the immediate function of a firewall in preventing unauthorized network access.