Cortana is Microsoft’s equivalent to Apple’s Siri and Google Now. Cortana is Microsoft’s digital voice assistant that will be available in Windows 10. Cortana voices are going to be customized to the user’s home country. Initially, it will be available in the US, UK, China, France, Italy, Germany and Spain. The rest of the world would have to wait. If you like to hear some voice samples, here is Time’s article about Cortana.