Cold may refer to any of the following:
1. When used as an adverb, cold describes anything that happens without advanced notice or an introduction. For example, with a computer, a cold boot is when the computer is turned on after being off for several hours.
2. With temperature, cold is a lower measure of heat either by perspective or reference. For example, as a computer is on and working, it produces heat and be hot. However, if it's off long enough, it becomes cool, or colder.
3. When describing a color, cold colors or cool colors are those such as blue, green, violet, or purple. These cool tones are associated with feelings of revitalization and calm. The opposite of cold colors are warm colors.