Internet

  • Internet is a gloabl network of interconnected devices or network of networks that allows devices to exchange data.
  • It communicate via standard protocols.
  • Protocols are rules or standards that define how devices communicate over a network.



History of Internet

  • The Soviet Union launched Sputnik 1 (first artificial Earth satellite) that pushes the United State to boost tech research.
  • The United State then formed the Advanced Research Projects Agency (ARPA), aiming to build a resilient communication system.
  • This eventually led to the creation of the ARPANET (Advanced Research Projects Agency Network), which introduced the concept of packet switching.
  • ARPANET successfully connected four universities and tested the idea of packet switching.
  • Initially, ARPANET used a protocol called NCP (Network Control Protocol), which allowed basic communication between hosts but wasn't scalable beyond ARPANET.
  • NCP was host-to-host protocol. It handled communication between hosts connected to the network.But NCP worked only on ARPANET.
  • To support a global, interconnected network, Vint Cerf and Bob Kahn developed the TCP protocol, which was later split into TCP + IP.
  • ARPANET officially switched to TCP/IP protocol.



Packet Switching

  • Packet switching is a method of breaking data into small chunks (called packets) and sending them independently across a network.
  • Each packet can take a different route to reach the destination, where they are reassembled in the correct order.
  • It uses bandwidth efficiently. Enables faster, more flexible communication
  • It is more resilient. If one path fails, packets can reroute.



TCP/IP

TCP/IP stands for Transmission Control Protocol / Internet Protocol. It’s the main set of rules (protocols) that allow computers to communicate over the internet. It is a set of communication protocols that ensures reliable data transfer across the internet

Internet Protocol

  • Assigns addresses to devices (like a home address).
  • Decides where each data packet should go.

Transmission Control Protocol

  • Makes sure the data arrives correctly and in the right order.
  • Resends packets if any are lost or broken.



How the Internet Works

  • We type a URL in our browser (like google.com).
  • The browser uses DNS to find the google's server's IP address.
  • The request is broken into packets and sent over the internet using TCP/IP.
  • Routers decide the best path for each packet.
  • The server receives the packets, processes them, and sends back a response.
  • Your browser reassembles the response and displays the webpage.