Microsoft's new Surfaces unit are now emerging in the market and people get a little confused about which to buy between the two. Sure, the two devices both have promising specs and performance but, unfortunately, only one device can be picked.

Let's look at the difference and which from Microsoft Surface Pro 4 and Microsoft Surface Book is much better. According to Gizmag, consumers who often used a laptop and have extra cash to spend should go for the Surface Book.

While, users who often spend time using a 2-in-1 tablet and need a much budget friendly device should opt for the Surface Pro 4. Surface Book has 21 percent bigger screen compare to Surface Pro 4, which enticed buyers who are more interested in a small and lighter unit.

As a tablet, Surface Book makes a "huge slate," but has an incredibly light feeling in hand. In fact, it's nine percent lighter than Core i5 and i7 Surface Pro 4 in spite of its bigger size.

However, it has a long battery life in laptop mode but only lasts up to an hour or two of use as a tablet between charges.

Meanwhile, here are the differences between Surface Book and Surface Pro 4 specs, as noted by CNET.

Surface Pro 4 has 12.3-inch display with 2,736x1,824-pixel resolution while Surface Book has 13.5-inch display with 3,000x2,000-pixel resolution. Pro 4 is quite bigger compare with 11.50 x 7.93 x 0.33 inches while the Book scales 8.67 x 12.3 x 0.30 inches.

However, they both running under Windows 10 Pro operating system and their processors are up to 6th-gen 2-core Intel Core i7. Pro 4 has Intel Iris 540 graphics while the Book already has Intel HD 520 or Nvidia GeForce.

They both have 128GB, 256GB, 512GB up to 1TB storage, Pro 4 has a variation of 4GB, 8GB and 16GB RAM while the Book has 8GB and 16GB RAM. Pro 4 can last up to 9 hours video playback while the Book can go up to 12 hours.

They both have 5MP front and 8MP rear camera, however, Pro 4 has Windows Hello face authentication. Surface Pro 4 has a starting price of $129 Type Cover or $159 Type Cover with a fingerprint sensor, stylus included.

Surface Book, on the other hand, starts with $1899, including keyboard dock with built-in Nvidia GPU and stylus. Prices will change for the much higher models with bigger storage.

Check this Microsoft Surface Pro 4 and Microsoft Surface Book review and comparison by Tested: