Cortana Windows Phone is the new Siri for Microsoft. Microsoft has just revealed its new mobile search assistant, Cortana, its own version of Siri and Google Now. Cortana Windows Phone is part of Microsoft's new Windows Phone 8.1 software, the mobile giant's first major update since last year.

Cortana Windows Phone is a "personal digital assistant" which has the ability to search the Internet, set up alarms, shift calendar appointments, find restaurants, send messages, place calls and more. Microsoft lifted the curtains on Cortana Windows Phone at its Build Developers Conference in San Francisco Wednesday.

Using Cortana Windows Phone is easy as it is very similar to using Apple's Siri. Push an on screen button, ask a question and Cortana is at your service.

Cortana Windows Phone also has the ability to get into apps and the phone's core services, offer the weather in your current location, inform you of your favorite sports scores, scan email, provide updates on a flight status, and even figure out what your habits are so it could predict your next move.

What does it have that other softwares don't? Cortana Windows Phone can actually take the results of its searches into the next level by moving over to other apps.

An example was demonstrated with the use of Bing health tracker app. At the Build Conference, Microsoft's Windows Phone design chief Joe Belfiore used Cortana to search for the number of calories in a banana. The results came back with the option to add the banana to Bing's health tracker as something he ate.

Cortana Windows Phone will be voiced via actor Jen Taylor to compete with Apple's Siri AI assistant. Jen Taylor voicing the software was just rumors before the Build conference, but the official announcement that the foundation for the company's AI assistant came in a preview of Windows Phone 8.1.

In the video above, Microsoft highlighted Windows Phone 8's other amazing features, but for gamers, Cortana Windows Phone being voiced by Halo's Jen Taylor is positively appealing.

Cortana in Windows Phone isn't the only new feature for Windows Phone 8.1. Microsoft's mobile OS now has a notification drawer called Action Center. This OS can now collect text messages, emails, calls and updates from social networks and other apps.

Meet Cortana on Windows Phone 8.1 on the video below.