This term is using when you want to describe something that spreads swiftly via the Internet. Meme is a cultural unit (an idea or value or pattern of behavior) that is passed from one person to another by non-genetic means (as by imitation); “memes are the cultural counterpart of genes”. So any unit of cultural information, such as a practice or idea, that is transmitted verbally or by repeated action from one mind to another can be called as Meme.
The British scientist Richard Dawkins coined the word “meme” in The Selfish Gene (1976) as a concept for discussion of evolutionary principles in explaining the spread of ideas and cultural phenomena. Examples of memes given in the book included melodies, catch-phrases, beliefs (notably religious beliefs), clothing fashion, and the technology of building arches.