Start Menu: After its hiatus in Windows 8, the Start Menu has returned. Utilizing a combination of the traditional menu system and Windows 8's Live Tiles, the improved Start Menu gives you more information at a glance, showing notification information alongside your applications and other pinned items.
Cortana: Microsoft's digital personal assistant, Cortana can answer your questions with information gleaned from both your device and the internet at large. You can type or even talk with her, if your system has a microphone. Using her Notebook, Cortana keeps track of your needs and wants, and she learns over time to improve her information gathering skills.