Simply, covalent compounds are where the electrons are shared by the atoms and ionic compounds are where electrons are donated from one atoms to another. We talked about compounds and molecules in the matter section. When we are discussing changes to matter, the changes are because of physical forces. When we talk about compounds they are formed and broken down by chemical forces. Compounds cannot be broken down by physical forces.
Chemical forces are forces caused by other compounds, or molecules.
There are millions of compounds everywhere. Chances are, everything you can see is one type of compound or another. When elements join together and become compounds they lose their individual traits. Sodium alone as an element is very reactive. The compound has none of the traits or the original elements.