A computer power supply is the most important component in your PC. It converts AC wall current into direct DC, providing stable and clean energy for all other components to work from!
Many power supplies have an 80 PLUS certification that classifies their energy efficiency. PSUs with the standard 80 PLUS (or higher) certification offer up to 85% efficiency at 20%, 50%, and 100% loads. There are also Bronze, Silver Gold Platinum Titanium versions which provide even more bang for your buck in high load situations!
Many PSUs feature hardwired cables to power all the CPU accessories. Modular computer power supplies offer flexibility, as they let you add or remove cables from inside your case for optimal airflow and protection against overheating in a single unit!