Realms

Minecraft Realms is a work-in-progress feature that, put simply, allows players to create and manage their own private server with minimal work and without the hassle of managing a custom server. Hosted by Multiplay through Mojang, Realms provides an easy and faster way to create Minecraft servers and allows the owner to manage their Realm from inside the game. Do take note, however, that Realms are not intended for large public servers, but for groups of friends or as a family server. Minecraft Realms is also on Minecraft: Pocket Edition in the form of Pocket Realms and is available to you if you have bought the PC version.

Availability
Realms is still in development and is subject to a limited release to certain countries. A subscription can currently only be purchased when living in one of the following countries and regions:

Subscriptions
Manage your subscriptions here.

Realms is a service that requires you to buy a subscription and renew it every time your current one expires. To do this, go to the link above, and it will let you purchase a subscription (check the Availability section to see if you can buy it.)

Here are the types of subscriptions and how long they last:

Managing a Realm
If you own a Realm, it can sometimes be slightly confusing what buttons do what. Here is a quick overview of the Realms menu:

Trivia

 * The Mojang blog closing signature was signed // The Minecraft and Minecraft Realms teams instead of the usual // The Minecraft team starting with the blog Minecraft Snapshot 13w09a.

Issues
The best way to report Realms bugs is to email the Realms support address, linked in the infobox above.

History
Minecraft Realms has been in development since Minecon 2012, when Mojang revealed that they wanted to host their own servers. At the release of Snapshot 13w09b (released in March 2013,) about 100 active players were selected by a computer algorithm to test the first alpha version of Realms. Later on, with the release of Minecraft 1.6.4, new Alpha Testers were chosen. Also, if you went to Minecon 2013, you received a Minecraft Realms prepaid card, which could be redeemed on Mojang's website for one subscription to Minecraft Realms (the subscription is valid for 30 days). Finally, on December 18, 2013, Minecraft Realms Beta was made available to the public of Sweden. Over the course of that day to the present, Minecraft Realms has become available elsewhere.