What does a bus in computer architecture primarily do?

A bus in computer architecture primarily functions to facilitate communication within the computer system, specifically by transmitting data between the CPU and memory. This function is crucial as it allows the CPU to retrieve data stored in memory for processing and to store results back into memory after computations are completed. The bus serves as a communication pathway that carries both data and control signals, ensuring that information can flow efficiently between various components of the system.

In contrast, while connecting input devices to the CPU is important, this role is typically fulfilled by specific interfaces rather than the bus itself. Similarly, powering the computer system falls under the responsibilities of the power supply and not the bus. Generating random numbers is a specialized function often handled by dedicated algorithms or hardware components, not by the bus. Thus, the exemplary purpose of the bus in facilitating data transfer between the CPU and memory makes it a critical element in computer architecture.