(Editorial note: Some of the terms used in today's Grammar Rules post are used in legal situations. I am not a lawyer, and this should not be considered legal advice.)
When it comes to libel and slander, we're really talking about different types of defamation. As such, a good first step in this post is defining defamation, which is the act of defaming, disparaging, or damaging the reputation of another person.
For it to be considered defamation, the person who attempts to damage the reputation of the other person must state the damaging information as fact (as opposed to their opinion), the act caused injury to the other person, and the damaging information itself must be false.
There are two main categories of defamation: libel and slander. So let's look at the differences between libel and slander.
Libel vs. Slander
For the most part, libel is considered defamation in a tangible form, such as writing, pictures (photos and drawings), and/or images. Most people think of it as "printed" material, whether in print or digitally, though Merriam Webster's includes "oral statements" in its definition of the term. With the advance of recordable and sharable media, this surely complicates the term, though defamation is defamation.
Slander, on the other hand, is strictly considered the act of orally telling one or more people defamatory statements about another person or entity. If a person were to tell a group of friends at a party that Mr. C's local restaurant cooks and serves expired food (and the statement were false), it could be considered slander, because it may negatively impact business at Mr. C's restaurant.
As mentioned earlier, the line dividing libel and slander may be blurring a bit with some online media (like YouTube and Instagram). If someone records a video in which they slander a person or business, is it still considered slander (because of its oral nature), libel (because it's published), or both? I'll leave that one to the lawyers out there, but it makes for some tricky definitions.
Here are a few examples:
Correct: Matilda's false tweets that Harold was fired from his last job for homicidal recklessness is libel, because now many of his regular customers won't go to his auto repair shop.
Incorrect: Matilda's false tweets that Harold was fired from his last job for homicidal recklessness is slander, because now many of his regular customers won't go to his auto repair shop.
Correct: At the party, Michael had a little too much to drink and began slandering half his co-workers.
Possibly incorrect: At the party, Michael had a little too much to drink and began libeling half his co-workers.
While technological advances may be blurring the line between libel and slander, a good rule of thumb for keeping these terms straight is to think of libel as a tangible form of defamation and slander as intangible. Or use this trick: Take the "s" in "slander" to think of someone "speaking" their defamation; and take the "l" in "libel" to think of someone being able to "lend" (or share) their form of defamation, because it's available in some tangible form (even if it's digital).
No matter what type of writing you do, mastering the fundamentals of grammar and mechanics is an important first step to having a successful writing career.