Understanding the Use of Http.router* in Web Development

const Login = Http.router
  .schemaSearchParams(S.struct({ a: S.string }))
  .pipe(Effect.flatMap((a) => Http.response.json({})));

const LoginRoute = Http.router.makeRoute("GET", "/login", Login);

const app = LoginRoute.handler.pipe(
  Effect.provideService(Http.router.RouteContext, { route: "??", params: {}, searchParams: {} }),
  Effect.provideService(Http.request.ServerRequest, Http.request.fromWeb(new Request(""))),
);