Question about Pre-release, pre-order, and CE

What is the difference between pre-release pack, a pre-order pack, and a Collector Edition Pack?

I know that the pre-release grants you a certain amount of gameplay time and 2 items for new proffessions. But what extras do the pre-order pack and CE provide? I think I read somewhere that CE gives the player special items?

Thanks

assuming you're talking about nightfall, the bonus for the pre-order was announced by Anet, and will include one extra character slot for your nightfall account, 2 pre-order items, and some other stuff. pre-order = pre-release i guess, as pre-orders are done pre-release :P When faction came out, people who pre-ordered had a 24h early access to the new continent.

I don't know what the extras will be in the Nightfall CE, usually it contains bonus stuff like poster, a CD, some other gimmicks, ... and something extra ingame, for phrophecies that was the "divine aura" (glowing hands), for factions it were the background dancers.