What makes English hard to learn for non-native speakers of English is that the language is full of double meanings. The pun is about wordplay that exploits those double meanings. Wikipedia defines a pun as:

“A joke exploiting the different possible meanings of a word or the fact that there are words that sound alike but have different meanings.”

A common kind of pun is based on homophones, two or more words that sound the same but have different spellings and meanings.

Funny Puns

Teacher: Tell me something that conducts electricity.
Student: Why—er—

Teacher: Very good—wire! Now, name a unit of electrical power.
Student: The what?

Teacher: Very good job—the watt is correct!.

Alfred Hitchcock famously said ‘Puns are the highest form of literature’.

Some famous people’s puns:

“I have mood poisoning. Must be something I hate.”
― Marilyn Manson[separator_dots]

“Over the years, I have been subjected to many indignities, all for the sake of Art. If I ever catch him, I’m going to kill the guy.”
― Bob Hope[separator_dots]

“Skinny jeans were only good if you had skinny genes.”
― Matt Dunn, A Day at the Office[separator_dots]

Visual puns about celebrity names have become very popular memes. These are images with two or more panels in which the first panel presents a celebrity or character captioned with his or her name, followed by a panel containing a pun of the name, editing the image to reflect the joke.  Apparently, it all started with a meme about Reese Witherspoon’s name in 2008.