A central processing unit (CPU) is the part of a computer that is in charge of interpreting and executing programs and coordinating the work of all other components.
A central processing unit, also known as a processor or CPU, acts as the “brains” of the computer — it is the component that performs the arithmetic, logic and control operations specified in any program. The concept of a CPU has been in use in computer science since as early as the 1950s.
Most modern CPUs are microchips containing millions of microscopic transistors. Each of those transistors can turn on and off, representing the ones and zeroes of the binary system. By working in combination, these transistors allow even smartphone CPUs to perform billions of calculations per second.
One of the primary characteristics defining the computational power of a CPU is its clock speed, usually measured in gigahertz (GHz), which very roughly corresponds to the number of calculations a CPU can perform per second.