If you have never played before with HttpService, I’d recommend you to take a look at this. In simple terms, it lets you make HTTP requests from your experience/server.
Sometimes you want to retrieve (GET) or send data (POST) to a proxy server/API you have mounted, this is the way. Recently I’ve made a copy game like Pls Donate, which required a proxy server to make requests and retrieve player’s inventory. This is a small example where you use HttpService. There’s also multiple methods like GetAsync, PostAsync or RequestAsync (which has more to deal with, and I highly recommend to use this last one over the others). But also there’s more methods which are more used like GenerateGUID (a random string that is used to give unique identifiers to certain objects, like pets for an inventory).
JSONDecode and JSONEncode when handling requests (GET and POST, depending on which one you’re making). There’s much more but I recommend to check it out. 