80 Plus is a certification of efficiency of the AC to DC conversion within a PSU. 80 Plus Certification does not mean a power supply will be 80%+ efficient 100% of the time; in fact, the 80 Plus certification only requires certain levels of efficiency at certain load levels. We have embedded a table below.
80 Plus has the normal 80 Plus certification alongside levels, including bronze, silver, gold, platinum, and titanium. It should be noted that the simply because a power supply does not have an 80 Plus certification does not mean it is inefficient, occasionally companies simply do not send in PSUs to be certified. 80 Plus levels are different for countries that use 230v wiring instead of 115v wiring. Australia, for example, uses 230v wiring. 80 Plus Certification is handled by Plug Load.
PSU Efficiency Chart