Microsoft has taken issue with Apple’s claims in several recent ads that its iPad Pro is a computer. In a new ad published on Tuesday, Microsoft (MSFT) compares the features in its Surface Pro 4 to the iPad Pro and uses Apple’s virtual personal assistant Siri to poke fun at the things Apple’s device can (and cannot) do.

The ad, which is called “What’s a computer? Just ask Cortana,” ends with a simple message: “Surface does more. Just like you.”

Microsoft’s shot at Apple (AAPL) comes after the iPhone maker has been making the pitch to consumers and business users that its iPad Pro, which launched last year, could actually be a suitable computer. In a series of ads it’s run over the last week, Apple has illustrated how its iPad Pro, with help from its cover accessory that doubles as a physical keyboard, can perform all the functions a computer can.

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“Just when you think you know what a computer is, you see a keyboard that can just get out of the way. And a screen you can touch—and even write on,” says one of Apple’s ad narrator as the iPad Pro is shown in-use. “When you see a computer that can do all that, it might just make you wonder, ‘Hey, what else could it do?’”

Apple’s ad ends with “Imagine what your computer could do if your computer was an iPad Pro.”

Some followers on Twitter (TWTR) and forum sites have criticized Apple for making the comparison, decrying that the iPad Pro is a tablet running a mobile operating system. They also noted that the iPad Pro can’t convert into a computer-like device with a screen and keyboard without the additional accessory. It’s perhaps also worth noting that Apple itself lumps iPad Pro sales into its iPad category on its financial statements.

http://www.youtube.com/watch?v=o_QWuyX8U18

Still, the Surface Pro 4 isn’t all that different from the iPad Pro, boasting a cover that doubles as a keyboard as well as a touchscreen. Microsoft is quick to note, though, that its tablet runs Windows—a desktop operating system—and comes with some traditional ports.

Regardless, the line between what is a computer and what’s not is blurring. Two-in-one hybrids, for instance, have become extremely popular in the computing market, and they, too, come with touchscreens and detachable keyboards.

Either way, Microsoft seems intent on proving that its tablet can do more than Apple’s—and proving the iPad Pro isn’t really a computer.

For more about Apple’s iPad Pro, watch:

Apple did not immediately respond to a request for comment.