What is a Firewall?
A firewall is a network security solution that monitors incoming and outgoing data packets to permit or block them based on a set of rules. It acts as a barrier between the guarded system and external sources to keep malicious traffic like viruses or hackers from entering your system and accessing private information or taking control of devices on the network.
Firewalls can be hardware or software, but both have similar functionality. In general, they are deployed as a network security device at the perimeter or as a program on computers running in a protected environment to provide protection against threats. They can also be used as a component of other security solutions such as antivirus or intrusion prevention systems.
Depending on the firewall type and settings, it can be used for unethical purposes such as government censorship or monitoring employee online activity to collect personal data, which infringes on privacy and individual freedoms. Firewalls can also be used for more benign applications such as content filtering to block websites that do not have a business purpose for employees. Moreover, they can be used to stop distributed denial of service attacks (DDoS) by preventing attackers from overwhelming a network with traffic to deny access. However, this requires a more multilayered approach that goes beyond traditional port/protocol inspection and blocking, and involves sandboxing technologies or threat intelligence to identify evasive behavior. This has led to the development of next-generation firewalls or UTM devices that integrate stateful inspection, application awareness and an IPS in a single system.