Defamatory, Libel, Slander

I heard a lot of people posting some unpleasant messages to others or even calling false statement in public. I am not familiar with all the laws but I am aware that any issuance of a false statement to others can be subject to defamation, libel or even slander depending on its case nature.

• defamation- issuance of false statement that can cause to other people to harm. For example posting it in facebook or any kind of public publications.
• Slander- it is a defamatory act that is usually represented orally...
•  Libel- the makings of the statement that involves publications, fixed medium such as magazines or newspaper.