Views in Rails work similarly to views in Sinatra, although Rails is more opinionated about where your views live in your application directory structure. The main difference is that Rails uses render to render views and partials, abstracting away the particular "format" of the view, e.g., ERB or something else.
In Sinatra we'd write something like
get '/users/:id' do
@user = User.find(params[:id])
erb :show_users
end