1. First of all, these are different operating systems and different hardware architectures, although now progress is aimed at unification. Let’s take, for example, such giants as Microsoft and Apple. MS has Surface laptop tablets based on ARM and Windows 10; Apple in June 2020 announced the transition to ARM architecture in computers.
2. The distinction in hardware resources is still relevant. The power of the insides and the amount of memory. Although, again, in 2020 this point is already losing its relevance. The power of the new flagship mobile devices is comparable to budget notebooks based on the x86/64 architecture. The power of budget and mid-priced mobile devices provides a level of performance suitable for most needs.
3. The most obvious difference in hardware apart from power is the presence of a variety of sensors and communication modules in a mobile device, as well as multiple cameras, vibration, a fingerprint scanner, etc.
4. The presence of an orientation sensor already suggests testing in portrait and landscape orientations. Add to this the variety of display resolution, their different types of matrices with their own display characteristics.
5. In a mobile device, a lot of attention is paid to handling various interruptions (incoming call, notification, pressing the lock button, unloading from RAM, etc.)
6. The main function of mobile devices is still communication. Voice communication, but also via mobile internet, which makes testing more difficult compared to desktops.
7. Communication in the context of interaction with wearable electronics (wireless headphones, fitness bracelets, smartwatches, glasses, etc.), contactless payments, etc.
8. Progress in OS updates. This happens much more frequently on mobile devices and is more important due to the great competition.
9. Differences in OS guidelines.
10. Desktop applications are most often downloaded from the manufacturer’s official website. A mobile app is almost always downloaded from the corresponding OS app store.
11. Expectations. Applications of desktop devices are made mainly for the implementation of certain functional activities and are working tools. For this reason, they can sometimes be forgiven for things that lead to the immediate removal of the mobile application and negative reviews. Any minor problem with intuitiveness, interface, localization, functionality, performance, battery consumption can instantly scare the user away and give preference to competitors.