Big tech companies are always having digs at each other, take Samsung's latest Apple-bashing ad for example, and Microsoft has joined in the fun with its new Windows Phone commercial. It's Cortana vs Siri.

One of the main new features of the Windows Phone 8.1 Cyan update is Cortana, a personal digital assistant, and that's exactly the focus of this 30 second clip. Microsoft shows off the features of Cortana by comparing it to Siri - although we're yet to see a full UK launch for Cortana.

The video is entitled 'Siri vs. Cortana - Happy Anniversary' and puts the Lumia 635, a notably budget mobile phone, against the iPhone 5S, Apple's latest and greatest flagship handset.

"Say hello to Cortana, your new personal assistant. Cortana will remind you to leave early to beat traffic and help you get to your destination on time, will remind you that you need milk when passing the grocery store, and will remind you to say happy birthday when your mom calls. Available now on the new Nokia Lumia 635 and on other Lumia phones." boasts Microsoft.

Cortana is given a set of different commands, all of which it is more than happy to help with such as reminding the user to buy roses when he is near a flower shop. Meanwhile, Siri concedes that it cannot carry out any of the tasks.

Eventually Siri admits "Now that, is a smart phone", but Microsoft states that screens are simulated and sequences have been shortened.