There are 2 kinds Data bus and address bus

data bus which carries the data ( includes both instruction and data).

address bus which carries where the data in the data bus must be sent to in the RAM or which I/O device has to be active to read / write data to the data bus .

Data bus

A communications bus which transfers information or data. Most busses are data busses.

This can include the Front Side Bus, PCI bus, Memory Bus, and more.

An Address Bus gives the memory instructions on where to place the actual data that it will stored or read. Basically a map location. The Data Bus carries the information that is going to be stored or read using the location that the Address Bus gave to the memory.

Address bus is unidirectional while data bus is bi directional

control bus