🔥 feat: add initial version of wiki page for firewall

hugo-blog/content/docs/roadmap/networking/concepts/firewalls.md

@@ -2,15 +2,36 @@
 title: "Firewalls"
 ---
 
-# 4th Level of Menu
+# Firewall
 
-## Caesorum illa tu sentit micat vestes papyriferi
+## Introduction
 
-Inde aderam facti; Theseus vis de tauri illa peream. Oculos **uberaque** non
-regisque vobis cursuque, opus venit quam vulnera. Et maiora necemque, lege modo;
-gestanda nitidi, vero? Dum ne pectoraque testantur.
+A **Firewall** is a network security device that monitors and controls incoming and outgoing traffic from a computer network. By allowing only authorized traffic and blocking unwanted traffic, firewalls protect against unauthorized access, malware, and other security threats. A firewall in a computer network provides security at the perimeter by monitoring incoming and outgoing data packets in network traffic for malware and anomalies.
 
-Venasque repulsa Samos qui, exspectatum eram animosque hinc, [aut
-manes](http://www.creveratnon.net/apricaaetheriis), Assyrii. Cupiens auctoribus
-pariter rubet, profana magni super nocens. Vos ius sibilat inpar turba visae
-iusto! Sedes ante dum superest **extrema**.
+Firewalls have been a first line of defense in network security for over 25 years. They establish a barrier between secured and controlled internal networks that can be trusted and untrusted outside networks, such as the Internet. A firewall can be hardware, software, software-as-a service (SaaS), public cloud, or private cloud (virtual).
+
+There are five main types of firewalls depending upon their operational method:
+- Stateless or packet filtering firewall
+- Stateful inspection firewall
+- Circuit-level gateway
+- Application-level gateway
+- Next-generation firewall (NGFW)
+
+## Learning resources
+
+### Books
+
+- [Firewalls and Internet Security: Repelling the Wily Hacker](https://www.amazon.com/Firewalls-Internet-Security-Repelling-Hacker/dp/020163466X)
+
+- [Building Internet Firewalls](https://www.oreilly.com/library/view/building-internet-firewalls/1565928717/)
+
+### Courses
+
+- [Network Security and Firewalls](https://www.coursera.org/professional-certificates/google-cybersecurity?utm_medium=sem&utm_source=gg&utm_campaign=B2C_EMEA_google-cybersecurity_google_FTCOF_professional-certificates_country-multi-non-mdf&campaignid=20858198836&adgroupid=156245838709&device=c&keyword=cyber%20security%20courses%20on%20coursera&matchtype=p&network=g&devicemodel=&adposition=&creativeid=684249172057&term{term}&hide_mobile_promo&gad_source=1&gclid=CjwKCAjw_e2wBhAEEiwAyFFFo-ImdGjo0e5NliYtn3cbyRmycSuHCwurR1v0Joa8Kh0ERlvs2Nn47RoCOnkQAvD_BwE)
+
+
+### Miscellaneous
+
+- [What Is a Firewall? Definition and Types of Firewall | Fortinet](https://www.fortinet.com/resources/cyberglossary/firewall)
+
+- [What Is a Firewall? - Cisco](https://www.cisco.com/c/en/us/products/security/firewalls/what-is-a-firewall.html)