Kyle Russell/Business Insider
But Cortana - named after the artificial intelligence character in Halo, Microsoft's flagship game series - is more than just a voice assistant.
During Microsoft's Joe Belfiore's demo, Cortana was able to set reminders, make phone calls, convert Fahrenheit to Celsius, pull up a list of nearby Mexican restaurants based on their star ratings, and more, all using Bing search.
But what's even more exciting about Cortana is that she can learn about you in a more dynamic way. During the demo, Belfiore asked that she remind him to ask his sister about her new puppy next time he talks with her. Cortana not only knows who his sister is, but also popped up a reminder later in the demo when she called.
She can also scan email and recognize things from email so she can prompt you about things like your travel plans, flights and when you need to leave for the airport.
"We think Cortana is the most personal digital assistant," Belfiore said.
Cortana is currently in beta, but she is able to work with third-party apps and more apps than just Windows core apps. That's something that Apple's Siri can't do - yet.