What is the difference between single phase and split phase?

The electrical distribution companies tend to erect their distribution systems on a hub and spoke basis with three phases out to a hub, and single phases to various users.

In order to balance consumption across the phases they tend to put one phase per street or per apartment block etc. In some locations they may install two 230/240V lines plus a common neutral, known as split phase. It is possible to connect the phase converter across the two live lines, in which case the phase converter is powered from 460/480 V. This has the advantage that the current consumption of the phase converter will be lower than for a 230/240 V single-phase connection.