Rule 34 is an internet meme, perceives as an adage “Rules of the Internet", a list of protocols and conventions which first appeared on 4chan. In asserts that "if something exists, there is porn of it"
Rule 34 is said to come from a comic posted on the website Zoom-Out. There, an image with a caption "Rule #34 There is porn of it. No exceptions" was drawn by Peter Morley-Souter to depict his shock at seeing Calvin and Hobbes parody porn.
Then in May of 2009, Something Awful's user Electric Eggs posted a thread titled "Ask me about inventing Rule 34", in which he claimed to have created the comic with his sister after learning the about the adage in an IRC chatroom.
The name first appeared in the Urban Dictionary in 2006, submitted by user Nukeitall, who claimed the adage was commonly used on a variety of message boards. Then On October 12th that year, the rule was included in the original "Rules of the Internet" list submitted to the Internet culture wiki Encyclopedia Dramatica.
When Rule 34 became a meme, it states that internet pornography exists concerning every conceivable topic. Since then, Rule 34 plays its role inside the ubiquity of internet pornography, especially among genres of fiction and hentai in which the characters engage in sexual behavior.
After Rule 34 became a hit, then came Rule 35 which states: "If no porn is found at the moment, it will be made."