[keycloak-user] How does a bearer only client validate

Hi All, I have two keycloak client one is a public client using implicit flow and authenticating the user via a redirect and then once the user is authenticate the client receives a token. This token is then passed to a REST based backend service which validate it before providing access to the API data. I am looking for more information on how does a bearer only client validates the token which it receives from the JavaScript based public client. I will also be interested to understand more about the relationship of these two clients based on scope to make this setup work -- PULKIT