What is the advantage of a three-phase power source versus a single-phase power source?

Three-phase power delivers balanced voltage across all three-phases.

Three-phase power delivers up to three times the amount of power of a single-phase power source.

Three-phase power cancels neutral harmonics on the 3rd, 5th, and 7th orders where Single-phase power does not.

Three-phase power does not require a neutral; therefore, you can attain increased levels of efficiency over single-phase power.