The Book 10 has a 10.6-inch 1080p screen, but it doesn't come with Samsung's AMOLED display.
It runs Windows 10 and your apps with a 7th-generation Intel Core m3, which has two cores and runs at 2.6GHz.
It comes with 64GB of storage, which you can expand with up to 256GB a microSD card.
The Book 12 has a 12-inch AMOLED display with a taller 3:2 display than the usual 16:9 widescreen. Taller screens are great for viewing websites, which are oriented more vertically than horizontally. That said, 3:2 screens leave less space for sharing the screen with other apps.
The Book 12 runs on a more powerful 7th-generation Intel Core i5u. It's also dual core, but runs at a faster 3.1GHz.
Built into the Book 12 is 128 GB of storage, which you can expand with up to 256GB a microSD card.
However, neither of the processors in the two Galaxy Book devices can match up against the processors in the Microsoft Surface Pro tablet PCs.