A firewall is a network security device used to monitor, filter and control data traffic to and from a network to protect the internal network from unauthorized access, malicious attacks and cyber threats. It can set up rules to allow or block specific types of traffic to pass through, thus ensuring the security and privacy of the network

In today's digital age, cybersecurity has become a major concern for businesses and individuals. With the popularization of the Internet and the development of technology, the risk of cyber-attacks is increasing. In order to protect the network from various threats and attacks, firewalls have become a crucial network security device. So what is a firewall and what is its role in network security?