The Four-Layer Network Stack

When you send data across the Internet, it doesn't just magically appear at the destination. It passes through four distinct layers, each with a specific job. The TCP/IP model divides network communication into these layers: Application (what you see), Transport (reliable delivery), Internet (routing), and Link (physical transmission). Think of it like sending a letter: you write the message (Application), put it in an envelope with address (Transport), the postal service routes it (Internet), and it's physically carried by van/plane (Link)!