title: Understanding the need of client id, client secret in oauth 2.0
body: <p>I have a web site that requires user to log in by providing their email and password to gain access token, where the access token token is used to access api.</p>
  
  <p>User can then gain access to read/write with the scope provided by the access token.</p>
  
  <p>So, what I would like to understand here is that what roles does client id and client secret play in such a case, and what benefits can implement client id and client secret provide? Because i really do not see the need of implementing client id and client secret since user may just use access token to gain access right.</p>