Types of things that are not considered matter include any type of energy, and abstract concepts. Everything in the universe that contains mass is made of matter. However, there are several things, such as heat, light and other forms of energy, that are not considered matter because they lack mass.
Time is another abstract concept that has no mass and therefore is not matter. A person's thoughts are not composed of matter. Sunlight and rainbows also have no mass. Other concepts or things that do not contain matter include sound, love, gravity, microwaves and memories. Information and personal reflections also are not matter.
