Defamation is not an offence, so people don't get prosecuted (what you meant by "charged") for it.
It's what lawyer's call a "civil wrong" - a problem between two parties that is not a crime.
Further to Tim W's comments, in order to establish an action for defamation, you need to prove 3 things:
1. information is communicated by the defendant to someone other than you;
2. the information identifies you; and
3. the information is defamatory - meaning that it could injure your reputation by exposing you to hatred, contempt, ridicule or cause others to shun you.