Yes, the token will be validated server side for every request. The server validation will provide also user information given by the token to be used next in server API code.
JWT validation will check only if the token is valid and return its value (JSON object), it is a very fast process that do not consume resources. Send an Authorization : Bearer <token> request header as standard procedure.
JWT is one of the best way for authorization as you can create RESTful solutions. (do not depend on web sessions anymore)
You may check the JWT first when you receive a request, validate it and next route the request to the module that handle it with added token information.