A CPU (Central Processing Unit) is the main “brain” of any device, including smartphones, responsible for executing instructions and running apps. Its clock speed, measured in hertz (MHz or GHz), shows how many cycles it can perform each second. Higher frequencies can mean more performance, but also more heat and power usage. Modern processors are engineered not just to tick faster, but to do more work per clock cycle, making architecture and efficiency just as important as raw GHz. In phones, the CPU sits inside a larger chipset (SoC) and plays a critical role in overall speed, multitasking, gaming, and everyday responsiveness. Because different CPU families handle work differently, clock speed alone is a poor way to compare devices-independent benchmarks and real‑world tests give a far more accurate picture of true performance.