Dual in-line memory module (DIMM) with an aluminium heat sink cover (blue and black). The heat sink absorbs and radiates away excess heat produced by the module while it is in use. A DIMM is a standard type of memory module used in computers. It consists of a several integrated memory circuits joined together to form a module. The contacts (yellow) are where it plugs into a computer motherboard. This is a G.Skill Ripjaws gaming memory module.