Matter is generally considered to be anything that has mass and volume. The volume is determined by the space in three dimensions that it occupies. The mass is determined by its rest mass (or invariant mass), which is measured by the acceleration a body has when a force is applied. The greater the mass, the slower the acceleration for the same force. Matter is thus a general term for the substance of which all observable physical objects consist. Typically, matter includes atoms and other particles that have mass, but this definition confuses mass and matter, which are not the same. Different fields use the term in different and sometimes incompatible ways; there is no single agreed scientific meaning of the word "matter," even though the term "mass" is better-defined.
Common definition
The common definition of matter is anything that has both mass and volume (occupies space). For example, a car would be said to be made of matter, as it occupies space, and has mass.
The observation that matter occupies space goes back to antiquity. However, an explanation for why matter occupies space is recent, and is argued to be a result of the Pauli exclusion principle. Two particular examples where the exclusion principle clearly relates matter to the occupation of space are white dwarf stars and neutron stars, discussed further below.
Atoms and molecules definition
A definition of "matter" that is based upon its physical and chemical structure is: matter is made up of atoms and molecules. As an example, deoxyribonucleic acid molecules (DNA) are matter under this definition because they are made of atoms. This definition can be extended to include charged atoms and molecules, so as to include plasmas (gases of ions) and electrolytes (ionic solutions), which are not obviously included in the atoms and molecules definition. Alternatively, one can adopt the protons
Baryonic matter
Baryons are strongly interacting fermions, and so are subject to Fermi-Dirac statistics. Amongst the baryons are the protons and neutrons, which occur in atomic nuclei, but many other unstable baryons, exist as well. The term baryon is usually used to refer to triquarks — particles made of three quarks. "Exotic" baryons made of four quarks and one antiquark are known as the pentaquarks, but their existence is not generally accepted.
Baryonic matter is the part of the universe that is made of baryons (including all atoms). This part of the universe does not include dark energy, dark matter, holes or various forms of degenerate matter, such as compose white dwarf stars and neutron stars. Microwave light seen by Wilkinson Microwave Anisotropy Probe (WMAP), suggests that only about 4.6% of that part of the universe within range of the best telescopes (that is, matter that may be visible because light could reach us from it), is made of baryonic matter. About 23% is dark matter, and about 72% is dark energy.
. Degenerate matter
In physics, degenerate matter refers to the ground state of a gas of fermions at a temperature near absolute zero. The Pauli exclusion principle requires that only two fermions can occupy a quantum state, one spin-up and the other spin-down. Hence, at zero temperature, the fermions fill up sufficient levels to accommodate all the available fermions and for the case of many fermions the maximum kinetic energy called the Fermi energy and the pressure of the gas becomes very large and dependent upon the number of fermions rather than the temperature, unlike normal states of matter.
Degenerate matter is thought to occur during the evolution of heavy stars. The demonstration by Subrahmanyan Chandrasekhar that white dwarf stars have a maximum allowed mass because of the exclusion principle caused a revolution in the theory of star evolution.
Strange matter
Strange matter is a particular form of quark matter, usually thought of as a 'liquid' of up, down, and strange quarks. It is to be contrasted with nuclear matter, which is a liquid of neutrons andprotons (which themselves are built out of up and down quarks), and with non-strange quark matter, which is a quark liquid containing only up and down quarks. At high enough density, strange matter is expected to be color superconducting. Strange matter is hypothesized to occur in the core of neutron stars, or, more speculatively, as isolated droplets that may vary in size fromfemtometers (strangelets) to kilometers (quark stars).
Two meanings of the term "strange matter"
In particle physics and astrophysics, the term is used in two ways, one broader and the other more specific. 1. The broader meaning is just quark matter that contains three flavors of quarks: up, down, and strange. In this definition, there is a critical pressure and an associated critical density, and when nuclear matter (made of protons and neutrons) is compressed beyond this density, the protons and neutrons dissociate into quarks, yielding quark matter (probably strange matter). 2. The narrower meaning is quark matter that is more stable than nuclear matter. The idea that this could happen is the "strange matter hypothesis" of Bodmer and Witten. In this definition, the critical pressure is zero: the true ground state of matter is always quark matter. The nuclei that we see in the matter around us, which are droplets of nuclear matter, are actually metastable, and given enough time (or the right external stimulus) would decay into droplets of strange matter, i.e. strangles.
Other types of matter
Ordinary matter, in the quarks and leptons definition, constitutes about 4% of the energy of the observable universe. The remaining energy is theorized to be due to exotic forms, of which 23% is dark matter and 73% is dark energy.
Dark matter
Main articles: Dark matter, Lambda-CDM model, and WIMPs
See also: Galaxy formation and evolution and Dark matter halo
In astrophysics and cosmology, dark matter is matter of unknown composition that does not emit or reflect enough electromagnetic radiation to be observed directly, but whose presence can be inferred from gravitational effects on visible matter. Observational evidence of the early universe and the big bang theory require that this matter have energy and mass, but is not composed of either elementary fermions (as above) OR gauge bosons. The commonly accepted view is that most of the dark-matter is non-baryonic in nature. As such, it is composed of particles as yet unobserved in the laboratory. Perhaps they are super symmetric particles, which are not Standard Model particles, but relics formed at very high energies in the early phase of the universe and still floating about.
Dark energy
Main article: Dark energy
See also: Big bang Dark energy
In cosmology, dark energy is the name given to the ant gravitating influence that is accelerating the rate of expansion of the universe. It is known not to be composed of known particles like protons, neutrons or electrons, or of the particles of dark matter, because these all gravitate.

Exotic matter
Main article: Exotic matter
Exotic matter is a hypothetical concept of particle physics. It covers any material which violates one or more classical conditions or is not made of known baryonic particles. Such materials would possess qualities like negative mass or being repelled rather than attracted by gravity.
Origins
The pre-Socratics were among the first recorded speculators about the underlying nature of the visible world. Thales (c. 624 BC–c. 546 BC) regarded water as the fundamental material of the world. Anaximander (c. 610 BC–c. 546 BC) posited that the basic material was wholly characterless or limitless: the Infinite (apeiron). Anaximander (flourished 585 BC, d. 528 BC) posited that the basic stuff was pneuma or air. Heraclitus (c. 535–c. 475 BC) seems to say the basic element is fire, though perhaps he means that all is change. Empedocles (c. 490–430 BC) spoke of four elements of which everything was made: earth, water, air, and fire.[57] Meanwhile, Parmenides argued that change does not exist, and Democritus argued that everything is composed of minuscule, inert bodies of all shapes called atoms, a philosophy called atomism. All of these notions had deep philosophical problems.
Aristotle (384 BC – 322 BC) was the first to put the conception on a sound philosophical basis, which he did in his natural philosophy, especially in Physics book I. He adopted as reasonable suppositions the four Empedoclean elements, but added a fifth, ether. Nevertheless these elements are not basic in Aristotle's mind. Rather they, like everything else in the visible world, are composed of the basic principles matter and form.
The word Aristotle uses for matter, ὑλη (hyle or hule), can be literally translated as wood or timber, that is, "raw material" for building. Indeed, Aristotle's conception of matter is intrinsically linked to something being made or composed. In other words, in contrast to the early modern conception of matter as simply occupying space, matter for Aristotle is definitionally linked to process or change: matter is what underlies a change of substance.
For example, a horse eats grass: the horse changes the grass into itself; the grass as such does not persist in the horse, but some aspect of it—its matter—does. The matter is not specifically described (e.g., as atoms), but consists of whatever persists in the change of substance from grass to horse. Matter in this understanding does not exist independently (i.e., as a substance), but exists interdependently (i.e., as a "principle") with form and only insofar as it underlies change. It can be helpful to conceive of the relationship of matter and form as very similar to that between parts and whole. For Aristotle, matter as such can only receive actuality from form; it has no activity or actuality in itself, similar to the way that parts as such only have their existence in a whole (otherwise they would be independent wholes).

Abaca
Despite its relative omnipotence (abaca is commonly used in clothes, rugs, tea bags and even dollar bills), not many people know about abaca. It’s found in certain banana trees, and can be found in the Philippines, Ecuador and Costa Rica.
Because the entire plant is used during the harvest of abaca crops, it’s seen as an ecologically friendly material. The actual material is tough and flexible, is widely used in industry, and is known informally as Manila hemp. Look out for it!

Bamboo
Bamboo is a much more well-known for various reasons, not least is affiliation with pandas, but also the fact that it can be used to produce pretty much anything; the technology that makes it possible to make bamboo cloth for instance is now available. The dexterity of bamboo combined with its fast growth rate – rendering the use of fertilizers and pesticide unnecessary – means the material is both green and competitive, the magic blend that eco-conscious entrepreneurs are constantly looking for.

Sea grass
A fairly strange material that is now being used to make anything from rugs to wicker work, sea grass is by is very nature stain-resistant, and strong and durable to boot (making it a good alternative to actual wicker).
Sea grass currently has two green attributes: the crop has only recently began to be harvested in significant quantities, meaning conservationists have been monitoring is development from the very early stages of its use, secondly, side-effects of its production includes the creation of ecosystems, stabilization of sea beds and protection against the erosion of coastlines.

Hemp
Given its mention earlier on, hemp was bound to be mentioned at some point. Famously part of the cannabis family, hemp is often used to make things like rope and netting but can also be used to create bricks and fuel. It also grows fast like abaca and bamboo, and can be used as a mop crop, which means that contaminants from soils can be soaked up by it.

Wood
A staple of human development for thousands of years, the ever-useful wood is unfortunately the material on this list that is to be exploited – and this exploitation carries through to the people and animals that share their environments with forests. Illegal logging leads to deforestation, and their relatively slow growth means that the impact on oxygen supplies, clean water and bio sustainability are some of the biggest problems we currently face.