Power supplies that use standard household electrical power are single phase AC converters. The input can be 120 VAC or 240 VAC in these applications. Normal power in the US is 60 Hz and 50 Hz is common in other parts of the world. Aircraft systems often use 400 Hz power at 115 VAC altough some applications use higher frequency power.
What is interesting to note is that AC to DC power converters are generally composed of two main elements: and AC to DC converter on the front end and a second DC to DC converter on the output side. The AC to DC section can be very simple (a rectifier and filter) or a more complicated power factor corrected (PFC) converter. This is generally a high voltage DC output without any isolation from the AC source.
The DC/DC section provides the isolation as well as changing the voltage from the high level to an acceptable level for the application. Many of these supplies provide multiple output voltages as well.