I've been hearing about a thing called realms, but I don't know what they are. Can someone please tell me about them?

Realms Is Multiplayer But Realms WAS NOT released till the future updates come so we are in 0.8.1 and in the future we will have realms

Written On: Jan 18, 2014
At 4:23 Afternoon
Location: Cebu City, Philipines