I think I have the definitions of fact and theory well in hand:
From Merriam Webster:
theory noun \th--r, thir-\
Definition of THEORY
1: the analysis of a set of facts in their relation to one another
2: abstract thought : speculation
3: the general or abstract principles of a body of fact, a science, or an art
4a : a belief, policy, or procedure proposed or followed as the basis of action
b : an ideal or hypothetical set of facts, principles, or circumstances —often used in the phrase in theory
5: a plausible or scientifically acceptable general principle or body of principles offered to explain phenomena
6a : a hypothesis assumed for the sake of argument or investigation
b : an unproved assumption : conjecture
c : a body of theorems presenting a concise systematic view of a subject
See theory defined for English-language learners
See theory defined for kids
Examples of THEORY
a widely accepted scientific theory
Her method is based on the theory that all children want to learn.
There are a number of different theories about the cause of the disease.
She proposed a theory of her own.
Investigators rejected the theory that the death was accidental.
There is no evidence to support such a theory.
He is a specialist in film theory and criticism.
The immune surveillance theory of cancer holds that in a way we all do have cancer, that a healthy immune system fights off rogue cells as they appear. —Sallie Tisdale, Harper's, June 2007
fact noun \fakt\
Definition of FACT
1: a thing done: as
a obsolete : feat
b : crime
c archaic : action
2 archaic : performance, doing
3: the quality of being actual : actuality
4a : something that has actual existence
b : an actual occurrence
: a piece of information presented as having objective reality
— in fact
: in truth
See fact defined for English-language learners
See fact defined for kids
Examples of FACT
Rapid electronic communication is now a fact.
The book is filled with interesting facts and figures.
He did it, and that's a fact.