It's yet another initiative to build low power, portable, and affordable computers for educational purposes, especially in the developing world. Previous attempts have not seen widespread success, such as the One Laptop Per Child initiative....
A week of Windows 10, holograms and Exploding Kittens on Mars
Office 2016 launching this year, touch apps coming soon
Microsoft reveals the next version of Windows 10
Introducing Windows 10 for phones
Hands on with HoloLens
Download: Windows 10 build 9926