How vk api client authorization works?

Question

JavaScript

Hello. In general, asking such questions on forums, etc. alien to me, but now I don’t even know how to ask this question to Google. How does user authorization work when working with vk api? I understand that the question is very generalized, but I stupidly do not know how else to ask it. I don’t understand the very principle of how VK authorizes a user on someone else’s site so that another site can somehow operate with the user’s information. I'm talking about client authorization .. although I don’t really understand server authorization either ... just now I decided to play around with these apis in javascript. Thanks

Answer 1

 Reading about OAuth2

Answer 2

I don’t understand the very principle of how VK authorizes a user on someone else’s site so that another site can somehow operate with the user’s information.

Let's take a login as an example. When registering on the site, the VK service gives personal data and a unique identifier, authorization also occurs through it. you request a login from VK, a bunch of routes, and everything arrives in the login widget on the site, which already processes it in its own way. something like this.