What is the difference between 3-phase and 1-phase?

Up to 10 Ampere standard applications are designed with phase power supply.

For conducting current larger than 10 A, especially for driving motors in industrial applications, all the applications are normally designed for three phase power supplies.

AnswerA three-phase system is more economical, in terms of the volume of copper required (around 75%), than a corresponding single-phase line supplying the same load. Three-phase systems deliver energy continuously, rather than in pulses. Three-phase motors are self-starting and more compact than a single-phase motor of similar capacity. Despite this, 'most' homes don't require three-phase supplies and are provided with a single-phase service (having said that, in some countries, such as Cyprus, three-phase residential supplies are common).