The document compares mobile and PC architectures and their impact on application development. Mobile architectures are SOC-based with limited standardization and peripherals integrated into the same silicon, making upgrades difficult. Resources like RAM, storage, and displays are more limited on mobiles. This requires optimizations like avoiding busy loops and polling. Connectivity is also less reliable than on PCs. Specialized hardware like cameras further impact application design. Future mobile architectures may include more multi-core CPUs and improved multimedia capabilities while still prioritizing power management and smaller form factors.