Microsoft ad says Apple's iPad Pro Smart Keyboard doesn't make it a real computer

While the rivalry between Microsoft and Apple has ebbed and flowed over the years, the new ad from the Redmond, Wash., software giant is a sign that things are once again heating up. In it, Microsoft's Cortana asks Apple's Siri why she is throwing a party —  Siri responds that the celebration is because the iPad Pro "just got a keyboard."

The iPad says to the Surface that it is "a computer now, like you."

The ad is in reference to Apple's own "What's a Computer?" ad that began airing earlier this month. Fifteen days after its debut, Microsoft has struck back quickly, in an effort to undermine the success of the iPad Pro lineup.

In its attack on the iPad Pro, Microsoft, notes that the Surface Pro runs a full-fledged Intel Core i7 processor, and is capable of running the full Windows version of Microsoft Office, not just a scaled-down app.

Cortana also notes that the Surface Pro's attachable keyboard has a dedicated trackpad for cursor input. The Microsoft tablet also differentiates itself by highlighting the availability of external ports.

The ad concludes with the tagline that "Surface does more. Siri, meanwhile, concedes that her keyboard-focused party "wasn't such a good idea."

Apple has been working to create a narrative for iPad Pro, positioning the tablet as part workstation, part play station. Historically, tablets are viewed as mere content consumption devices, as they lack the hardware and software assets required to run professional applications.

Apple's iPad lineup continues to greatly outsell the Microsoft Surface. Even in a head-to-head matchup of tablets with detachable keyboards —  a market Apple just entered last fall with the 12.9-inch iPad Pro — the iPad continues to outperform the Surface.

iPad sales have steadily been on the decline for a few years, but their overall revenue grew last quarter, bolstered by the launch of the premium 9.7-inch iPad Pro, which starts at $599. The jumbo-sized 12.9-inch model, meanwhile ranges from $799 to $1129 before adding in optional accessories like the Apple Pencil or detachable Smart Keyboard.