This question already has an answer here:
- Lemma vs. Theorem 6 answers
What essentially is the difference between a lemma and a theorem in mathematics? More specifically, suppose you come across a general result while solving a mathematical problem, what are the characteristics you would look for before categorizing it as a theorem or lemma?
EDIT: Does a difference of personal perspective count? Does the effort which goes into deriving a result also determine this distinction? I mean if the result is obtained by one person by a simple algebraic manipulation or trivial reasoning and by a complex derivation by another(let's suppose that this second person stumbles across this result while attacking a totally different problem from the first person), then I suppose the first person would call it a lemma and the second person a theorem? (Assuming that the result has great applications.)
PS: This question is the duplicate of another question (by Tamaroff) which is more comprehensive and has excellent answers. But as a result of Jim's last comment below, I have an important doubt, which I think needs to be cleared. This doubt has not come up in the question (by Tamaroff). So I think this post should not yet be closed. I have edited my question to include the doubt, which I raised in my comment below, in the question.