Silence Mechanics

Can anyone help to explain why silence works in different way on different champions and their abilities? If you silence in his ult, the ult gets cut short. If you cast silence on during her charge, it stops.

But if you silence while his E is active, it doesn't dissipate. And supposedly if you silence while her ult is out, her ult doesn't go away.

I understand to a point that the abilities that are being canceled are ones that have a type of channeling to it before it can be used (like with and ). So then I would assume that if I were to silence while his E is active that it won't go away because it is an active ability and not a type of channel ability.

So do I just have the wrong concept of silencing in this game? From what it seems, silencing just prevents the user from activating abilities. If that were the case, shouldn't abilities like 's charge continue going until the timer runs out or until the silence runs out and the user could still cast her charge a second time to get it off? Or with 's ult, the silence could just run out if applied early and he's be able to get a cast off at the tail end of the channel. Unless silence cancels the channel to prevent that last minute chance of recasting the ability to get it off.

I'm not sure, just something I'd like some help clarifying.