MEME for Today
A 'meme' is a virally-transmitted cultural symbol or social idea.
The majority of modern memes are captioned photos that are intended to be funny, often as a way to publicly ridicule human behavior. Other memes can be videos and verbal expressions. Some memes have heavier and more philosophical content.
The world of memes (which rhymes with 'teams') is noteworthy for two reasons: it is a worldwide social phenomenon, and memes behave like a mass of infectious flu and cold viruses, traveling from person to person quickly through social media.
According to Cecil Adams of theStraightDope.com, the concept of memes "is either really deep or really, really obvious."