The TARDIS is a time machine and spacecraft in the British science fiction television programme Doctor Who . The name is an acronym of T ime A nd R elative D imension (or Dimensions) I n S pace.
A product of Time Lord technology, a properly maintained and piloted TARDIS can transport its occupants to any point in Time and Space. The interior of a TARDIS is much larger than its exterior, which can blend in with its surroundings through the ship's chameleon circuit. In the series, the Doctor pilots an unreliable, obsolete Type 40 TARDIS whose chameleon circuit is stuck, giving it the shape of a 1950s-style London police box .
The Doctor's TARDIS is an obsolete "Type 40 TT capsule" that he unofficially "borrowed" when he departed his home planet of Gallifrey.
The 2011 episode "The Doctor's Wife" provided an unprecedented insight into the TARDIS. The "soul" of the ship is transferred into the body of a humanoid female called Idris, and this enables the Doctor to have a conversation with his craft.