Desert

Desert is a nonbasic land type used for cards that depict a sandy or rocky region that is arid because of little rainfall and supports only sparse and widely spaced vegetation or no vegetation at all.

History
The subtype was created in the Eighth Edition rules update when all land types were cleaned up. For a long time, the only card featuring the subtype was the archetypal Desert from Arabian Nights. It was printed as such in Time Spiral/Timeshifted.

Apart from the ability to tap for colorless mana, the original Desert also has the ability to do 1 damage to attacking creatures. The subtype was needed because the Camels and Desert Nomads are immune to damage done by deserts, and refer to them by type.

Amonkhet finally featured four deserts, mirroring the harsh and punishing deserts of Egypt. They were inspired by the original card. The original Desert was not reprinted because, according to Mark Rosewater, it slows games down and isn’t fun.

The theme evolved quite a bit with Hour of Devastation, which features fifteen lands with the Desert subtype and sixteen cards that mechanically care about Deserts (there's some overlap between those two lists).

Ruling

 * Desert is a land subtype with no special meaning. It doesn't grant the land an intrinsic mana ability. Other cards may care about which lands are Deserts.

List of desert cards

 * Cradle of the Accursed
 * Desert
 * Desert of the Fervent
 * Desert of the Glorified
 * Desert of the Indomitable</c>
 * Desert of the Mindful</c>
 * Desert of the True</c>
 * Endless Sands</c>
 * Grasping Dunes</c>
 * Hashep Oasis</c>
 * Hostile Desert</c>
 * Ifnir Deadlands</c>
 * Ipnu Rivulet</c>
 * Painted Bluffs</c>
 * Ramunap Ruins</c>
 * Scavenger Grounds</c>
 * Shefet Dunes</c>
 * Sunscorched Desert</c>
 * Survivors' Encampment</c>

List of cards caring about deserts

 * Camel</c>
 * <c>Desert Nomads</c>
 * <c>Desert's Hold</c>
 * <c>Gilded Cerodon</c>
 * <c>Hashep Oasis</c>
 * <c>Hour of Promise</c>
 * <c>Ifnir Deadlands</c>
 * <c>Ipnu Rivulet</c>
 * <c>Ramunap Hydra</c>
 * <c>Ramunap Ruins</c>
 * <c>Sand Strangler</c>
 * <c>Scavenger Grounds</c>
 * <c>Shefet Dunes</c>
 * <c>Sidewinder Naga</c>
 * <c>Solitary Camel</c>
 * <c>Wretched Camel</c>

Amonkhet

 * The Broken Lands

Dominaria

 * Erg Mirab
 * Megheddon Defile
 * Great Desert
 * Sand Seas
 * Sukurvian Desert
 * Surr
 * Western Wastes

Mirrodin/New Phyrexia

 * Glimmervoid

Rabiah

 * Karun Desert

Rath

 * Flowstone Desert

Shandalar

 * Osai Desert

Tarkir

 * The Shifting Wastes

Ulgrotha

 * Dead Zone

Trivia

 * Many lands that are technically deserts are instead typed as plains, such as Esper's dunes or Tarkir's deserts. This comparison seems to be directly referenced in the flavor text of a Dungeons & Dragons: Adventures in the Forgotten Realms.