What is a Firewall?
A firewall is a network security solution that prevents unauthorized access to internal networks and devices by monitoring and controlling network traffic according to predefined rules. Firewalls are critical to a strong cybersecurity foundation, guarding against various types of cyber threats including malware, phishing attacks, backdoor hacking, spam, spyware and other intrusion attempts like DDoS attacks.
A firewall checks each incoming packet of data to determine its destination, its source or both and decides whether to let it through or reject it. It also evaluates the content of each packet to check for specific keywords or other criteria that might signal a malicious transfer. It then applies a set of filters to the data to allow it through or block it.
A firewall also typically supports a wide range of networking protocols, enabling it to be used as an intermediary between internal systems and external servers. This functionality is known as Proxy Services, and it allows the firewall to act as a filter that can control what information flows through a particular connection and how it’s transmitted.