Distinction One : Micro and Macro
In this context "micro" refers to the "level" of the individual — what goes on inside her head and how she acts. "Macro" refers to external facts about the world, especially the sum total of the actions and predilections of other individuals.
An axiom of sociological theory is that there are big things (bigger, that is, than individuals) and there are little things (individual actors) and that the latter react with the former and that the former are at least in part a result of the latter.
One approach to sociological theory would be to remain at the macro level and only ever try to explain macro things (riots, for example) in terms of other macro things (collective anger).
As humans studying humans, though, we are to explanations that involve human actors and human actions.
Axiom 1. There are individual actors, they are "the same" and they are "all different"
Axiom 2. Actions of individuals accumulate and aggregate and form part of the environment which conditions their actions