5. Understanding HTTP for backend engineers, where it all starts

backend is huge and if we start discussing every single component that could be part of it we will be stuck here for years so what we will do is we will only discuss those topics which are used in majority of the code bases let's say 90% of them with that in mind let's

talk about HTTP protocol the medium through which our browsers talk to our servers either to send data or to receive data from it and as I said there are a lot of other ways and protocols which clients and servers use to communicate with each other and HTTP being one of the most used ones we will

focus on that now there are two ideas which are at the heart of HTTP protocol the first one being tessness what does it mean tessness basically means it has no memory of past interactions so each HTTP request carries all the necessary information for the server to process it such as headers or URLs and methods

which we will see in a bit and after the server responds it forgets about the request if a client makes another request the server treats it as a new and unrelated event and it also means self-contained requests since the server does not remember pass requests each request must include all the necessary data such as authentication tokens or

session information to handle that specific interaction for example in the case of accessing a user profile the client has to provide credentials like cookies or tokens on every request for for the server to know which user is requesting the data so what are the benefits of that what are the benefits of this stateless model the obvious one

being Simplicity stateless design simplifies server architecture because the server does not need to store session information which would otherwise require additional resources and complexity and it also means scalability stateless protocol makes it easy to distribute request across multiple servers because no single server need needs to keep track of a session and if the server crashes it