RGB 4Pin 12v Connector
RGB or ARGB headers are both used to connect LED strips and other 'lighted' accessories to your PC. That's where their similarity ends.
An RGB header (usually a 12V 4-pin connector) can only control colors on a strip in a limited number of ways. For example, multiple colors on distinct parts of a single strip aren't possible severely limiting the lighting choices at your disposal.
That's where ARGB headers come into the picture. An ARGB, or Addressable RGB, header (usually a 5V 3-pin connector) supports devices equipped with an IC (Integrated Circuit, also sometimes referred to as a microchip) to provide much better flexibility with regards to lighting options.