The method Kb.bp() can be used for sudden changes. For example when you open a window, add an object, show a menu or close the application. Like this:
if(Kb.bp(KB_F1)) CreateObject();
Imagine you would use the method Kb.b() instead. As long as the F1 key is held down, a new object will be created. On a fast computer, this would be about 60 times a second. And even when you’re really fast and release the key almost instantly, you will probably create more than one object.
Still, this is a usable method, but only when you need gradual changes. Like when you move a dot to the right as long as a key is held down:
if(Kb.b(KB_RIGHT)) point.x += 0.01;
Every frame, the value of x will increase a little bit. The dot will gradually move to the right.