There are 3 different types of Gore-Tex generally used in motorcycle jackets & Trousers. (slightly different for gloves & boots etc)
You have Z Liner gore-tex which is quite simple, it's a zip in gore-tex layer which is removable so you can put it in your jacket and take out when needed - great for those who don't want much bulk and know if they'll be riding in rain or not. Gore-Tex liner is small enough to carry whereever you go too just in case you get caught out.
Second option is performance shell. Which is a gore-tex lining built into the jacket. It can't be removed, and it's protecting and bonded onto cordura layers generally. it's 100% waterproof like all gore-tex is, but the downside to it is that your clothing will still soak the water up, so you'll ride out in the rain, get home and you'll be completely dry but your clothing will have soaked up quite a bit of liquid. Takes a while to dry so not perfect for those that ride every day, but for the slightly more "casual" riders, it's brilliant.
Pro shell is the more expensive option, but as you'd expect by far the best. The gore-tex lining is bonded to the outer layer of the jacket, creating a completely seal - meaning the water can't even get through the first layer of the clothing. This means you can go out in pouring down rain, get home and shake your jacket and trousers off, they'll dry very quickly and shouldn't be an issue to use the next day
There is a lot more in depth to go with Gore-Tex, but above is a quick overview. If you have any questions, please don't hesitate to ask!