From wikipedia
A meme (rhymes with “dream”) is a unit of information that replicates from brains or retention systems, such as books, to other brains or retention systems. In more specific terms, a meme is a self-propagating unit of cultural evolution, analogous to the gene (the unit of genetics). The term was coined by Richard Dawkins in his controversial bestselling book The Selfish Gene. The concept predates the coining of the term; for example, William S. Burroughs asserted that “Language is a virus”. Memes can represent parts of ideas, languages, tunes, designs, skills, moral and aesthetic values and anything else that is commonly learned and passed on to others as a unit. The study of evolutionary models of information transfer is called memetics.