Why do you use attr_reader when you also use @ in action methods?

[MincePie]

I saw in the user policy example you have, you use:

class UserPolicy
attr_reader :current_user, :model

def initialize(current_user, model)
@current_user = current_user
@user = model
end

def index?
@current_user.admin?
end

I thought the point of attr_reader was to set access to the local variable. If that's the case, why do you use '@' in the action methods? Shouldn't your notation be 'current_user.admin? in the action methods?

I'm trying to learn how to write scopes and getting very stuck with the examples I can find to this point. I think my struggles have something to do with the notation. I'd love to know why you use this format. It might help me understand what's going wrong for me.