The notion of categorical imperatives is a

A categorical imperative is a moral law binding unconditionally.

In Kant's ethics it commands an action as good in itself, without any 'if' condition.

It contrasts with a hypothetical imperative, which binds only relative to a desired end.

Because it holds for all rational beings as such, it functions as a universal moral law.

The categorical imperative is thus the supreme principle of morality.