Internal Storage

In addition to RAM, your tablet will have internal storage space and possibly removable storage space. Internal storage allows you to install apps and store files, and removable storage allows you to expand this capacity. On computers, this internal storage was traditionally through a hard disk, but most tablets use a solid-state drive (SSD), like USB thumb-drives. Solid-state drives don't need to spin, so they're instantly available when you turn on your device.

Looking at the Xoom as a starting point, the minimum internal space you'd want to see is 16 gigabytes of space. A tablet with less space will work; however, if you use your tablet heavily, eventually you'll fill up the drive with books, pictures, apps, and files.

In addition, SD storage is a way to add capacity for your tablet if you find you're filling up all the space. Not all tablets offer SD storage, so you'll have to check to see if it's offered for the tablet you'd like to purchase. Motorola rushed the Xoom to market without SD storage, but started offering free upgrades in late September of 2011.