I know what damping is but I have no idea what resonance is? Please explain it in simple words.
There's a beautiful thing called "Google" search on the internet.
Don't do that too much! You'll cause resonance!
Well, personally I find there is reason in such question and the answer from Wikipedia, found by Google IMHO is meaningless, even I may dare to say - incorrect, because as cited in that part it contains implication that resonance is some internal characteristic of a system /like "specific frequency" is/, or possibly state, yet /evidently/ the authors themselves immediately after that continue by explaining resonance as "occurence" /as something that "occurs"/, "phenomena" involving more terms and such meaning "something what happens" and thus not being an internal characteristic or state of a system /however you define a "system" as something with a physical meaning/.
Excuse me for my possibly imperfect English as it's not my mother's tongue.
They are both correct. Words can mean more than one thing. So if an object has a resonance and is stimulated by an external agent with a frequency that matches the resonance frequency, a resonance will happen.
Separate names with a comma.