I guess almost everyone of you has an idea about what a Touch Tablet PC is but sometimes those concepts need to be explained better and I think the best way to describe a Touch Screen Tablet PC is by comparing it with laptops, the device it uses as a base to build upon this niche gadget.
Why is it a niche gadget? Firstly, because it's not something everybody would use or pay more than on a regular notebook/netbook. Basically a Tablet laptop is a more expensive Laptop that adds touchscreen capabilities for user input. But now let's take this matter in detail and compare a laptop and a touch screen tablet with the same specs like they were build by the same manufacturer and the only difference comes from the touch screen part.
Google Android 10 Tablet Pc
Main differences between a touch enabler notebook PC and a normal laptop:
Screen: it's thicker on a Tablet PC because of the additional layer (capacitive or resistive) and the electronics that control it and determine the user input precise location. Additionally the screen can pivot 180 degrees to allow a more comfortable use folded over the keyboard
Stylus: a Touch tablet features a pretty big display, but precise actions from the user need a stylus, especially in applications like Adobe Photoshop
Battery life: as touch screen tablets have more components than other laptops (the touch enabling layer over the display for example) the power consumption is slightly higher than on normal laptops so expect a shorter battery life away from the socket
Software: this is maybe the biggest difference, as without proper software and programs to take good use of the touch capabilities of a Tablet PC there isn't much to do with one. This is also what Tablet PCs lack right now but maybe manufacturers will understand this and will try and offer customized apps for touch input.Those I think are the most notable differences between a laptop and a touchscreen tablet PC. If you know more let me know in comments and I'll update it accordingly.