An Internet meme (/ˈmiːm/ meem) is an activity, concept, catchphrase or piece of media which spreads, often as mimicry, from person to person via the Internet. Some notable examples include posting a photo of people lying down in public places (called "planking") and uploading a short video of people dancing to the Harlem Shake.
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. These small movements tend to spread from person to person via social networks, blogs, direct email, or news sources. They may relate to various existing Internet cultures or subcultures, often created or spread on various websites, or by Usenet boards and other such early-internet communications facilities. Fads and sensations tend to grow rapidly on the Internet, because the instant communication facilitates word-of-mouth transmission.
Internet memes are a subset that Susan Blackmore called temes—memes which live in technological artifacts instead of the human mind.
Image macros are often confused with internet memes and are often miscited as such, usually by their creators. However, there is a key distinction between the two. Primarily this distinction lies within the subject's recognizability in internet pop-culture. While such an image may display an existing meme, or in fact a macro itself may even eventually become a meme, it does not qualify as one until it reaches approximately the same level of mass recognition as required for a person to be considered a celebrity.