An RGB controller is a central unit used to control and synchronize the color lighting of various computer components, such as fans or CPU coolers. It allows for the unification of lighting effects and colors across several devices at once. Instead of each fan glowing differently, you can set all components to have the same color or transition smoothly in one shared effect. It functions as a small box into which cables from individual RGB elements are plugged. The controller itself then connects to the power supply and the motherboard, which enables control via software on the computer. Some models can also be controlled by an external remote control. It is important to distinguish between standard RGB and addressable RGB, often referred to as ARGB. While in standard RGB all LEDs on a component glow in one color, ARGB technology allows each LED to be controlled individually. This creates more advanced effects, such as a "running rainbow." The controller must always be compatible with the type of lighting your components use. Thus, the controller resolves situations where the motherboard does not have enough connectors to plug in all lighting elements, or when you want to achieve a more complex and unified visual appearance for the entire computer build.