Hello there and welcome to my first blog post. I am Sijibomi Ajayi a software developer based in Lagos, Nigeria. I intend to use this space to share my knowledge and write on topics I feel are crucial in becoming a software developer. This post is the first of a backend developer series where I will be sharing my knowledge and documenting my journey in backend development.
The first topic I will be writing on will be :
The Internet
The internet is a large network of interconnected computers communicating together from different regions around the world. The internet was invented in the 1960s as a US army funded project. The first demonstration of the internet was on October 29, 1969. An organization as part of the research, connected four major computers from four different universities together. The connected computers were able to access files and transmit information among each other. More and more computers were added to the network. This was the building block of what is known as the internet today.
How does the Internet work ?
The internet is a large connection of interconnected networks. what then is a network? A network consists of two or more computers that are connected either physically(through an ethernet cable) or wirelessly(through bluetooth or wifi). Computers can be connected directly to each other in a network. This is totally fine if it's a network of two or three computers. This type of connection gets complicated when you are trying to connect say 10 computers together. Connecting it this way would require nine cable be plugged to each computer, the network quickly becomes complicated and messy! The solution to this problem is introducing a "central computer" which all other computers will be connected to. This central computer is known as a router. The router is a computer that acts as a middleman between computers on the network. The router makes sure that information transferred across a network are sent to the intended receiver. Every message sent on the network goes through the router. Computer A can send a message to computer B on the network by sending the message to the router, specifying the target computer. The router then forwards the message correctly to the intended receiver (computer B). Adding a router to the network quickly reduces the level of complexity of the network. Wireless connection of computers in a network works similarly, all computers are connected wirelessly to the router.
Private networks can be connected together by connecting their individual routers. The router it self is a "central computer" so it can be connected with various routers from different networks. By connecting routers together, a large network that accommodates an infinite amount of computers is created. The next question becomes, how are these routers from all around the world connected? How do you connect a router to millions of other routers to make the internet? Routers are connected to other routers over a telephone network. The router is connected to a telephone network through a MODEM. The modem (modulator demodulator) is a device that produces a signal that can be easily transmitted over a telephone network, and decoded reliably to reproduce the original data. The modem modulates the information sent from the sender into transmittable signals which will be demodulated into the original data on the receiving network.
To send message across networks we need to connect our network to an internet service provider. The internet service provider helps to connect our network to other networks around the world. A message from our network is sent through the Internet service provider to a target computer on a receiving network. Internet service providers offer services like internet access, domain name registration and more.
In my next post I will be exploring how computers identify each other over the internet. You might be curious as to how computers specify a target computer they are sending a message to.