Difference between 1U and PSII power supply

[timtim1065]

Hello,
I am researching for a power supply that provides an ATX connection to a min-itx motherboard as well as a 24V supply for motors. A site i researched has power supplies in the "1U" and the "PS II" category. Can someone point out the difference/standards for these two types? Thanks.

 

[canadian69]

PSII is a standard ATX type power supply.
1U is a "one unit" high power supply, which are made for rack servers. 1U is a unit of measure used in racks and rack equipment.