Microsoft has released a 30-second video spot that pits the iPad Pro against the Surface Pro 4.

Microsoft published the video, "What's a computer? Just ask Cortana", to YouTube on August 16.

The video spot -- presented as a conversation between Siri and Cortana -- highlights the differences between an iPad Pro, which is fitted with Apple's detachable keyboard (something Apple has been touting in a new commercial), and a Core i7-based Surface Pro with its detachable keyboard. The Apple keyboard doesn't have a trackpad, and the iPad Pro doesn't have multiple USB ports like the Surface Pro does, as Microsoft's ad makes sure to mention.

The new ad also calls out the fact that Apple's iPad Pro isn't able to run "full Office", which is true, since the iPad Pro is an iOS and not an OS X device. However, when Apple took the wraps off the iPad Pro last fall, Microsoft was part of the launch, touting availability of Office 365 and support for the Apple Pencil for the device.

Microsoft tag line for its Surface Pro devices are "tablets that can replace your laptop". Microsoft is positioning Surface Pro 4 as a head-to-head competitor with the iPad Pro.