Is your data safe on the Internet? Are you sure if you are web surfing right on the Internet? So let's start.
For a connection with a Server, you just need its IP address, and we can start communicating, this is called Direct Dedicated connections. But the Internet doesn’t work on Direct Dedicated connections, it means you are not directly connected to Servers.
Data on the internet travels in small packets of Information. We can only send all the information from one computer to another through IP packets, but there are some limits. Information is broken into pieces and travel through various routes and reach the destination system. Each broken packet has an internet address of where it came from and where it’s going. Some special computers on the Internet are called Routers which act as traffic managers to keep the packets moving through the network smoothly. If one route is congested, individual packets may travel different routes through the internet and they may arrive at the destination at slightly different times or even out of order. Every router keeps track of the multiple paths for sending packets, and it chooses the cheapest available path for each piece of data based on the destination IP address for the packet. If something goes wrong, the network can keep sending packets because having many options for the path, make it Fault-tolerant. This is the key principle of the Internet: Reliability.
How can we be sure if data is 100% delivered?
So now comes the Transmission Control Protocol(TCP), which manages the sending and receiving of all of your data as packets. TCP checks the data inventory and sends back the acknowledgments of every packet received and arranges the order of packets received. If TCP finds some packets are missing, those packets will resend from the server, until TCP gives a signed acknowledgment.
TCP and Router systems are scalable, the more number of routers we add, the more reliable the Internet becomes, and the more Fault-tolerant.