What is the purpose of the term 'Matter'?

[Aerion]

I will preface my question with the fact that I am a high school student with only a general knowledge of physics, though I have learned about a variety of phenomena at the limited level of depth that I am capable of. I am curious about several concepts and observed phenomena that are fundamentally important to our understanding of the universe, but seem to be nebulously defined. Among these terms, 'matter' is of the greatest concern to me. I have seen it defined, variously, as the amount of particles, mass, or even 'stuff' in an object. 'Stuff', obviously, is insufficiently clear to be used. Particles, while more specific, appears fundamentally flawed as the basis for matter, because particles themselves are generally considered to have matter (Particles meaning elementary particles). So only mass is left. Why, then, do we use 'matter' when we already have a more-clearly defined term, mass? If my understanding of these terms is incorrect, and this is the cause of my confusion, please let me know as well.

 

[electric jake]

Matter is defined as anything that occupies space and has mass. While mass is defined as something that represents the amount of matter in a particular space or particle. Matter can be measured using volume weight and many other units while mass is only measured in kilograms . They use matter to better explain observations happening in space, for example if i say "this cup has 200 milliliters of liquid inside of it" you can visualize that as being 1/5 of a liter but I can't tell you how much space something takes up with mass in that example if I said "this cup has 200 grams of liquid inside of it" you would know the mass of the liquid but you wouldn't be able to visualize how much space that mass would take up unless you knew what the liquid is and what it's density is to convert it into a volume representation and/or matter representation.Hope I helped.

 

[e.bar.goum]

I will preface my question with the fact that I am a high school student with only a general knowledge of physics, though I have learned about a variety of phenomena at the limited level of depth that I am capable of. I am curious about several concepts and observed phenomena that are fundamentally important to our understanding of the universe, but seem to be nebulously defined. Among these terms, 'matter' is of the greatest concern to me. I have seen it defined, variously, as the amount of particles, mass, or even 'stuff' in an object. 'Stuff', obviously, is insufficiently clear to be used. Particles, while more specific, appears fundamentally flawed as the basis for matter, because particles themselves are generally considered to have matter (Particles meaning elementary particles). So only mass is left. Why, then, do we use 'matter' when we already have a more-clearly defined term, mass? If my understanding of these terms is incorrect, and this is the cause of my confusion, please let me know as well.

This wiki article is a good start, and I would encourage you to read it: https://en.wikipedia.org/wiki/Matter

Key excerpts:

Before the 20th century, the term matter included ordinary matter composed of atoms and excluded other energy phenomena such as light or sound. This concept of matter may be generalized from atoms to include any objects having mass even when at rest, but this is ill-defined because an object's mass can arise from its (possibly massless) constituents' motion and interaction energies. Thus, matter does not have a universal definition, nor is it a fundamental concept in physics today. Matter is also used loosely as a general term for the substance that makes up all observable physical objects.

and

Matter should not be confused with mass, as the two are not quite the same in modern physics.[7] For example, mass is a conserved quantity, which means that its value is unchanging through time, within closed systems. However, matter is not conserved in such systems, although this is not obvious in ordinary conditions on Earth, where matter is approximately conserved. Still, special relativity shows that matter may disappear by conversion into energy, even inside closed systems, and it can also be created from energy, within such systems. However, because mass (like energy) can neither be created nor destroyed, the quantity of mass and the quantity of energy remain the same during a transformation of matter (which represents a certain amount of energy) into non-material (i.e., non-matter) energy. This is also true in the reverse transformation of energy into matter.

 

[DrClaude]

The difference between mass and matter is matter takes into account the gravitational force exerted on the mass. Mass is the same regardless of where an object is in the universe. However, matter changes depending on the planet's gravity. So this is why matter exists. It can be viewed that mass is intrinsic, while matter is extrinsic.

This is completely incorrect.