When you buy a power supply to build a desktop computer, one of the aspects that will usually be shown, in addition to the electrical power requirements that it can supply, is the efficiency of the power supply.
This is usually shown in the 80 PLUS rating, which is an efficiency standard managed by CLEAResult, which is still used today. In short, to receive this 80 PLUS rating, a power supply must show an output efficiency of at least 80 percent at 20 percent, 50 percent and 100 percent of the power supply's load value.
The ratings shown include 80 PLUS Bronze, Silver, Gold, Platinum and Titanium, which show increasingly higher efficiency values, beyond 80 percent. Recently, CLEAResult has introduced the new 80 PLUS Ruby rating.
The 80 PLUS Ruby standard rating is the most stringent rating for a power supply, as the efficiency value required for each percentage of the load value of a power supply must be higher than 90 percent. They also explained that this rating will be used for power supplies for cloud and AI data centers.