1) Molecular compounds - two or more non-metals elements/atoms coming together
2) Ionic compounds - one type of metal element/atom and one type of non-metal coming together
Actually, how you determine if a set of elements coming together is a MC or IC entails more understanding than stated above. These details will be discussed or taught in a separate location.
Chemical Formula
Another question one may have is, How many atoms of each element is coming together to form these compounds. Chemists have a short hand method to show this called Chemical Formulas.
Def Chemical Formula - a way of showing what elements are coming together and how many of each.
The chemical formula uses the chemical symbol of each element and a subscript that indicates how many atoms of each element are coming together to form the compound. Here are two examples including their chemical name:
1) Na1Cl1 - Sodium chloride (an Ionic compound).
2) C1O2 - Carbon dioxide (a Molecular Compound).
For our purposes here, you can say that:
1) In one ionic compound's base unit of Na1Cl1, there is one atom of Na and 1 atom of Cl (not actually correct but will explain elsewhere).
2) In one molecular compound's base unit of C1O2, there is one atom of C and two atoms of O.