Different components of the motherboard of a PC unit are linked together by sets of parallel electrical conducting lines. What are these lines called?

These lines are called “bus” or more specifically, they are referred to as “buses” in the context of computer motherboards. Buses are critical for the transfer of data, power, and signals between the different components of a computer, such as the CPU (Central Processing Unit), RAM (Random Access Memory), and various peripherals. Different types of buses exist for specific purposes, including the data bus, address bus, and control bus, among others.