Repeat after me ... GOOGLE.

1) An Internet meme is an activity, concept, catchphrase or piece of media which spreads, often as mimicry, from person to person via the Internet.

2) A meme is "an idea, behavior, or style that spreads from person to person within a culture". An Internet meme may take the form of an image, hyperlink, video, picture, website, or hashtag. It may be just a word or phrase, including an intentional misspelling.