Apple has announced its first foldable smartphone, the iPhone Duo, which has drawn comparisons to Microsoft's Surface Duo line of foldable devices. The name has sparked discussion, as Microsoft previously used "Duo" for its Surface Duo products, launched in 2020. Apple, however, has used the term "Duo" before, notably with the PowerBook Duo, a laptop introduced in 1992 that could connect to a desktop setup using an accessory called the Duo Dock. Apple also holds a trademark for the MagSafe Duo Charger, introduced in 2020, which charges two devices at the same time. Microsoft's Surface Duo was a compact phone and tablet hybrid with two screens connected by a hinge. It ran on Android and included features such as 360-degree rotation, but it was criticized for its performance as a tablet. The Surface Duo 2, launched in 2021, had a more reliable hinge but was still considered disappointing by some reviewers due to issues with its software and camera. Microsoft has since canceled plans for a Surface Duo 3 and has not pursued further foldable devices. Apple's iPhone Duo, while not groundbreaking, marks a shift for the company as it enters the foldable smartphone market. Early hands-on experiences suggest it may perform well in multitasking, similar to the Surface Duo 2. The use of the name "Duo" by both companies has led to debate, with some arguing that Apple is not entirely original in its naming choice, given its past use of the term. However, Apple's entry into the foldable market could signal a broader trend in smartphone design, as more companies explore new form factors to meet consumer demand for flexibility and innovation.