What are the differences between primary wire and secondary wire in terms of their functions and applications?

Primary wire is used for transmitting electrical power from a source to a load, while secondary wire is used for distributing power within a system or device. Primary wire is typically thicker and can handle higher voltages, while secondary wire is thinner and used for lower voltage applications. Primary wire is commonly found in automotive and industrial settings, while secondary wire is used in electronics and household appliances.