OIC now ... OH! I See Now!
We are posting Facts, Opinions, Concepts, Theories and stuff we just find interesting. Concepts are ideas, Facts are verified truth, Opinions are just what a person thinks about something (and doesn't mean it is true), and Theories are ideas that try to explain whatever they are about ... like the Theory of Relativity in Physics.
Do not get confused between what is fact and opinion.
Theories try to explain how things happen or work, and then are tested to see if they prove out to be fact.
Concepts are ideas on how to do something or how things work. There are proven concepts (Facts), and unproven concepts (Ideas)!