Update 100-osi-model.md (#1497)

content/roadmaps/102-devops/content/103-networking-protocols/100-osi-model.md

@@ -1 +1,15 @@
-# Osi model
+# OSI Model
+
+Open Systems Interconnection (OSI) model is a **conceptual** model consists of 7 layers, that was proposed to standardize the communication between devices over the network. It was the first standard model for network communications, adopted by all major computer and telecommunication companies in the early 1980s.
+
+<ResourceGroupTitle>Free Content</ResourceGroupTitle>
+<BadgeLink colorScheme='yellow' badgeText='Read' href='https://www.cloudflare.com/en-gb/learning/ddos/glossary/open-systems-interconnection-model-osi/'>What is OSI Model?</BadgeLink>
+<BadgeLink badgeText='Watch' href='https://www.youtube.com/watch?v=dV8mjZd1OtU'>OSI Model</BadgeLink>
+
+# TCP/IP Model
+
+TCP/IP model is a **practical** model consists of 4 layers. The modern Internet is based on this model.
+
+
+<BadgeLink  colorScheme='yellow' badgeText='Read' href='https://www.geeksforgeeks.org/tcp-ip-model/'>What is TCP/IP Model?</BadgeLink>
+<BadgeLink badgeText='Watch' href='https://www.youtube.com/watch?v=F5rni9fr1yE'>OSI vs TCP/IP Model</BadgeLink>