The Apple A4 is a system-on-a-chip (SoC) designed by Apple Inc. and was first introduced in 2010. It was used in devices like the iPad and the iPhone 4, marking Apple's entry into creating its own processors. The A4 integrates a central processing unit (CPU), graphics processing unit (GPU), and memory controller, allowing for efficient performance in mobile devices. The A4 chip is built on a 45-nanometer process and features a single-core ARM Cortex-A8 CPU. This architecture provided improved performance and energy efficiency compared to previous chips, enabling longer battery life and smoother operation in applications and games on Apple's devices.