What is a meme?
A meme (pron.: /ˈmiːm/; meem) is "an idea, behavior or style that spreads from person to person within a culture." A meme acts as a unit for carrying cultural ideas, symbols or practices, which can be transmitted from one mind to another through writing, speech, gestures, rituals or other imitable phenomena.
Supporters of the concept regard memes as cultural analogues to genes in that they self-replicate, mutate and respond to selective pressures.
What is a meme on the internet?
An Internet meme is a concept (usually a picture or video) that spreads via the Web. The word "meme" comes from the Richard Dawkins Book "The Selfish Gene" (1976). What he called a meme refers to a broader category of cultural information.
Memes spread rapidly on the Internet for many different reasons. The internet's sheer information density allows a concentration of memes that was impossible with any other forms of media. (from Wikipedia)