What is the main function of the Central Processing Unit (CPU) in a computer?

The main function of the Central Processing Unit (CPU) in a computer is to execute instructions and process data. The CPU is often referred to as the brain of the computer because it performs the fundamental operations of the system, which includes fetching instructions from memory, decoding them to determine the action to be taken, and executing those instructions to perform calculations or manipulate data as required by software applications.

This execution cycle is crucial for running programs and performing tasks, making the CPU integral to overall system performance. Without the CPU effectively processing instructions and managing data operations, a computer would be unable to function as intended, leading to a lack of responsiveness to user inputs or failure to carry out applications.

Options that focus on storing and retrieving data, managing user interfaces, or connecting to external devices describe functions that are performed by other components of the computer, such as storage devices, user interface hardware, and peripheral controllers. These actions support the CPU but do not represent its primary role. Hence, the focus on executing instructions and processing data highlights the CPU's essential purpose in a computer system.