Internet and Web programming
The Internet is a vast network of computers, and servers, which communicate with each other. The internet connects with the whole wide world together. How does it actually work at a very low level?
First, when we type a URL like www.google.com, the browser converts it into a file containing:
- GET /HTTP/1.1 (where GET means we are requesting some data from the server and HTTP refers to a protocol that we are using, 1.1 refers to the version of the HTTP request)
- Host: www.google.com
- And some other information
Now this file is converted to binary code by the browser and it is sent down the wires if we are connected through Ethernet and if we are using WiFi, first it converts it to a radio signal which is decoded by a router in a very low level. It is converted to binary and then sent to the servers.
This information or ‘binary codes’ go to the destination and respond if it is received by the sender only because of the IP address.
One router will send the information to another and this keeps on going until the binary codes reach the destination.
Now the server receives the binary code and decodes it and sends the response in the following manner:
- HTTP/1.1 200 ok (where 200 ok is the status)
- Body of page
Now, this is converted back to binary by the server and sent to the IP address that is requesting it. Once the codes are received by the client, the browser again decodes the information in the following way:
- First, it checks the status
- It starts reading the document from the HTML tag and constructs a Tree-like structure.
- The HTML tree is then converted to corresponding binary code and rendered on the screen.
- In the end, we see the website front-end.
Below is the tree structure of the HTML document:
The following diagram show the whole process:
To understand the basic web terminology refer: The Internet and the Web