Hello there
As an ex. lawyer, it's easy to differenciate between the two forms of defamation, libel and slander.
Essentially, Libel's something which is perminately recorded, substantially untrue and will affect that persons reputation. Slander, however, is something which isn't perminatent (something spoken in presence of minimum ofthree people), is substantially untrue and will affect that persons reputation.
Hope that helps.
G.