Richard Dawkins introduced the term meme in his 1976 book The Selfish Gene for a cultural unit of imitation.
Dawkins formed “meme” from the Greek word mimēma, meaning something imitated, while also making it resemble “gene.” He proposed memes as cultural replicators: ideas, behaviors, tunes, or practices that can spread from person to person and change through copying and variation.
The modern internet meaning developed later. Online memes are usually images, phrases, or formats that people copy and modify, but Dawkins’ original idea was broader and was intended as an analogy with biological evolution. A meme is not a DNA sequence, and cultural transmission does not follow exactly the same inheritance rules as biological reproduction.