"Memes" are cultural symbols and social ideas that spread virally. In the same way that a flu bug travels from person to person, memes travel through social media and email.
Memes are often things of minor consequence: jokes, urban legends, human and animal oddities. But in some cases, memes are art and music curiosities, and even philosophical ideas worth repeating.
Modern memes commonly take the form of photos and videos/animations/songs.
Here are the most popular modern internet memes today.