hello all ,first timer,can any one explain to me the difference between single and double poles in electrics?

Answer 1

Single poles are simple switches.
Double poles are two switches that have been ganged together (mechanically linked together) to operate in unison.

Answer 2

In a simple form single pole switches operate anything running on one phase of a panel, double pole switches operate anything running on two phases in a panel. For instance, in your home, lights are on single pole switches because they run on 110 volts. The hot water heater or well pump will operate on a double pole switch because they run on 220 volts.