Non-matter are concepts and things that do not possess mass or take up physical space. Non-matter objects typically do not carry a scent, nor can they be tasted or touched. Various forms of energy are typically considered to be non-matter.
Anything that exists in the known universe can be categorized as either matter or non-matter. Some everyday examples of non-matter objects include light that is emanated from a torch as well as the heat that is generated by a fire. Sound, such as those emanated by speakers or a police siren, is also considered to be non-matter.
Abstract concepts, such as information and memories, are also considered to be part of non-matter. These concepts exist as part of the observable universe, but they do not have any physical material presence and cannot be observed using standard methods.
Not all things that cannot be observed are considered non-matter. Certain objects, such as the air or the scent emanated by perfume, are invisible to the naked eye but are made up of matter as their existence can be verified using either smell or taste. Another example of non-observable matter are atoms, which can only be seen under microscopes by bouncing light off them.