Matter, is anything that takes up space
Matter can be solid, liquid, or gas. Matter is everywhere, being that air is considered matter.
Matter can be two things, matter can be pure substance or a mixture.
A pure substance is a substance made of one atom or type of molecule. A pure substance can be either an element, which is a pure element alone. A compound which is a pure substance containing two or more atoms chemically bonded to each other.
A Mixture is either a Homogeneous or a Heterogeneous, Homogeneous being a solution which is the same substance throughout, while a Heterogeneous is called suspension and is visibly different throughout. A colloid is a Homogeneous solution with intermediate particle size between a solution and a suspension.