What are WebSockets? How is it different from HTTP?

hey everyone welcome back my name is mehul and in this video we'll be taking a look at http vs websocket very two popular protocols which you use on the internet all the time without realizing also if you're new here make sure you like and subscribe to the channel i'm creating a lot of interactive and awesome content here at goddamn and even at codedam.com platform so if you want to stay in touch make sure you subscribe and hit the bell icon let's go so http is the protocol which you always use when you're browsing websites like google facebook code damn code dumps learning path and basically anything which you browse on the internet which starts with http or https that is done using http protocol so let's see what exactly happens when you write google.com and press enter on the http front it's not on the dns front on the http front so when you write http google.com what happens is that the first thing which your browser does is that it establishes after the dns resolution and the ip address has been figured out is that it establishes a tcp connection between your computer which you have here and the server which is owned by google right so this tcp connection is also called as layer 4 protocol the tcp protocol is called layer 4 in the osi model and these are just some layers of how the networking stack works physical layer then you know it goes on top and top and there are more and more abstractions we are not going to get into that but what you have to understand is that this connection is duplex so tcp connection is duplex and after some handshakes once it's established then what http does is that http in this case your computer right here says the standard things which you see get slash and you know this is the path for example get slash abc and then the http headers and this is sent to your server your server receives this part inside of tcp packet and responds with the correct document and that is it that is all http does right it just does this part particular communication and then closes off so what http does is that it only allows communication in a single direction so either the client speaks and the server response or the server speaks and the client response tcp on the other hand is inherently a two-way communication where both client and server can speak at the same time now you might think that why is that limitation for http it seems like a limitation right if you're going up the stack and you're kind of like losing the access to the to the functionality of both the people talking to each other there's a good reason for this this is because http as a protocol is stateless so this protocol is stateless that means every single time every single time if client wants to send something to the server the client has to specify all the headers that is the cookie header the authentication header whatever headers it wants and it has to send all of them to the server why this is a good thing because this allows http to stay stateless that means you can have multiple servers at the back end handling different requests right so it simplifies your architecture of scaling a lot horizontal scaling a lot right because now you can have a million clients here requesting the same page and this all the backend has to do is add more servers in order to serve these individual requests why because after every single http request that http connection gets closed tcp connection is open if you have a keeper live header but let's just assume for the sake of simplicity that this connection gets closed and the next time the next request arrives the next request is made by the client this connection might establish to some other server right and because this is stateless the other server exactly knows what the client wants websockets however behave in a slightly different way because they actually operate much more like how tcp works in terms of dual communication so of course websockets also works on tcp layer 4 communication layer 4 protocol and on top of this sometimes what you will see is that the initial request which the server sends is an http request to a websocket endpoint the client sends this request the server says that hey we can have a connection upgraded to websocket it also asks like can the connection be upgraded to websocket it says yep i can upgrade that connection to websocket and once that is done this connection is it's not exactly dropped but it's upgraded to our websocket connection and this websocket connection right here is awesome why because this actually is a dual channel established between the client and the server so how you can imagine this you can imagine this in the following way that this has actually called you know i'm just trying to draw a simple mobile phone this has actually called this server right here so both of them are now on a phone call where they pretty much can say whatever they want to each other any time of the day how does this differ from pc uh from your http that differs in the sense that your http connection is more like sending a letter which probably the symbols would for later also would seem seem the same but i'm just writing an l here so you send a letter once then the server reads it then the server responds with another letter and that's it the connection then closes right for the next time the client has to again initiate the connection or the server can as well if it knows the ip then in that case server becomes the client but you get the idea so this is just like a one-time transaction which is happening here but a major fault which you will observe here is that we lose that scalability aspect which we talked in the last video right because now if this client starts sending a thousand messages then only this server has to handle it why because they are on a phone call right so it cannot really drop the connection because if it do that then it pretty much will you know just drop the connection here and the client will see that hey the connection has been lost and the state has been lost for the most part because because this is a single connection now this connection is stateful that means it's not that on every single message this client has to tell who the client is right that authentication phase only happens when there is a handshake going on for the very first time after the handshake is complete this is a stateful connection to put this thing in another way your client establishes a tcp connection once that is established then your client establishes an http connection and tries to upgrade the socket to upgrade the connection to websocket once that has happened then this connection is upgraded to a stateful connection right here right now it can send some messages it can send some messages at any single time this has the drawback that you cannot use multiple servers to handle multiple messages because this channel is already established and it's long running right this problem does not happen in case of http because you can have multiple servers and all it is doing is just handling this one single request and that's it then it's closed then for the next request another channel opens up right and then that happens so it seems like websockets is fundamentally not horizontally scalable because you will always have this problem where a server is stuck with a client right and that is partly true but there are very interesting solutions like aws api gateway which allows you to address certain problems and we will definitely see how we can scale websocket connections in some further videos but i hope this gave you an understanding of how websockets differ from http there are some obvious differences as well for example http is definitely slower because you are transferring a lot more data in every single request compared to websockets websockets are long living therefore they are obviously faster as well because it's like on a phone call this is more like sending a letter or maybe like you know just giving a ring and then or sending a text message for example but yeah i mean both have their own pros and cons right so it's it's not like one is perfect for a single job it depends on what you want to do so yeah that's pretty much it for websockets versus http let me know in the comments what you think about this video and this video format in general i hope this video was able to provide you some value if it did make sure you like and subscribe thank you so much for watching and i'm gonna see you in the next video [Music] you

Channel: codedamn

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Keywords: web development, codedamn, mehul mohan, full stack development, full stack web development, http vs websockets, websockets vs http, what are websockets, websocket server, websocket framework, web socket example, websocket example, how is websocket different from http, secure websockets, What are WebSockets, How is it different from HTTP, webdev, app development, lesson, tutorial, websockets, webrtc, webtransport, js, nodejs, socket.io, websockets tutorial, chat app, javascript

Id: xTR5OflgwgU

Length: 8min 46sec (526 seconds)

Published: Wed Aug 25 2021