Data communication and OSI layer Model

  🌐 Introduction Have you ever wondered how your WhatsApp message or an email reaches from your device to someone else's device across the world? Behind this communication lies a well-structured system called the OSI Reference Model . OSI (Open Systems Interconnection) is a conceptual framework used to understand and design how data travels from one computer to another over a network. 📘 What is the OSI Model? The OSI Model was developed by ISO (International Standards Organization) in 1984. It consists of 7 layers , each responsible for a specific function in data communication. Full Form: OSI – Open Systems Interconnection Type: Conceptual (Theoretical) model Purpose: Standardize communication between different systems 🧱 7 Layers of the OSI Model (Top to Bottom) 1. Application Layer (Layer 7) This is the layer closest to the end-user. It provides network services directly to user applications like browsers and email. Functions: ✅ Web browsin...

  🧠 Goals and Applications of Computer Networks 🎓 Explained with logic, tricks & real-world examples 📘 Introduction – Why Networks? Imagine a classroom where students can’t talk to each other. Or 10 computers in an office, but none of them connected. That’s a disconnected world. Now imagine: One computer has internet Another has a printer Third has your favorite movies Still, you can access all of them from any system. That’s what computer networks make possible. A network is like the nervous system of technology — it connects , shares , and communicates across distances. 🎯 Goals of Computer Networks – What Do They Really Do? ✅ 1. Resource Sharing “Why buy 10 printers when one printer + network = win?” Networks allow multiple users to share: Printers Files Internet connection Applications (like MS Office, Photoshop) ➡️ Cost saved. Efficiency gained. ✅ 2. High Reliability “If one path fails, another opens.” Like Google Maps r...