This article explores the critical role of firewalls in network security. It covers the evolution of firewalls, from basic **packet filtering firewalls** that use **access control lists (ACLs)** to control traffic, to advanced **stateful inspection firewalls** that track connection states. The article also discusses **application layer firewalls** which analyze data content, and **nex... https://www.alifconsulting.com/post/introduction-to-firewall