When Apple unveiled the iPad in 2010, Steve Jobs presented the tablet as a third device that we could carry along with a computer and smartphone.

Years later, Microsoft responded with a radically different approach: It designed its Windows operating system to work on personal computers and tablets at the same time so that we could have both devices in one product.

Microsoft’s vision of a two-in-one tablet PC has now crystallized with the $1,000 Surface Pro X, which arrives in stores this week.

The 13-inch tablet attaches to a keyboard to convert into a laptop. It is Microsoft’s latest Surface to include a so-called ARM processor , a type of power-efficient chip used in many mobile devices, enabling apps to open more quickly and the battery to last longer. It also includes cellular connectivity to work with data plans offered by carriers like Verizon and AT&T.