The difference between a single phase and a three phase electric meter and service are that the three phase meters use 3 incoming wires to supply the voltage needed.
Single Phase meters and electrical services use 2 wires to supply the voltage.
Three phase meters and electrical services are used in areas that require a lot of energy, such as industrial areas where large appliances are used.
Single Phase electric service is used for mostly residential places and small businesses that only need a smaller use of electricity.
Single Phase electricity works with 2 wires but three phase electricity service works with only 3 wires.
The other difference between 3 phase and single phase electricity service is the voltage supplied to the meter and meter box.
With single phase electric service there's 240 volts of electricity being supplied to the electric meter and with three phase electric service it's usually 400 volts to 415 volts of electricity being supplied to the electric meter.