The iPad is a computer of sorts, but it uses a different type of processor than a standard computer. Along with all the components are on a single board, not modular like desktops and laptops.
The ipod touch and the ipad are the same except the ipad is bigger than the ipod.
Both an iPad and a fourth generation iPod Touch can use the same Messages app, so yes.
An iPad is an Apple electronic like an iPod touch. iPods are smaller than iPads but they are still the same except the size
pretty much the same just that the ipad is bigger
Yes, the cord used for a iPod can be used for a iPad. All of apple products use the same cord.
Yes. The iPod Touch, the iPhone, and the iPad all use the same App Store.
If by this you mean how does the audio quality compare between the iPod and the iPad, the iPad has better speakers, however the quality is the same using headphones or an external portable speaker.
Yes all apple ipod,iphones and ipad use same usb cable.
Script
It means jailbreaking iPod Touch - the same way you would jailbreak iPhone or iPad.
iPad
no the iPad 3, is acually called the iPad Mini, and no i believe it is half the size of the current iPads, making it bigger than the iPod touch.