The document summarizes the key components and types of computer power supplies. It discusses the main parts of a power supply including the metal coating, switch, fan, and current input. It then describes the most common power supply formats: ATX, SFX, TFX, Flex ATX, and custom formats for servers. It provides details on the ATX, SFX, and TFX formats and their typical maximum power capacities. The document also explains 80 Plus power supply certification and the different tiers from White to Titanium in terms of minimum power efficiency levels delivered under varying load conditions.