A data bus is a communication pathway within a computer system that carries binary data between major hardware components such as the central processing unit (CPU), main memory (RAM), and input/output (I/O) devices. It forms part of the system bus architecture and is responsible specifically for the transfer of data values, as distinct from addresses or control signals.
The width of the data bus, measured in bits (for example, 8-bit, 32-bit, or 64-bit), determines how many bits of data can be transferred simultaneously in a single bus cycle. A wider data bus allows more data to be moved per clock cycle, increasing data throughput and potentially improving overall system performance, particularly for memory-intensive operations.