WHAT ARE THE PROPERTIES OF SUPERCONDUCTORS?
Superconducting materials exhibit a variety of interesting characteristic properties.

1. Zero resistance allows large and heavy conventional cables to be replaced with small, light superconducting cables:
(Cables used at CERN for carrying 12.5kA. At the rear are conventional cables; in the foreground is a superconductor.)
Image taken from Wikimedia Commons

2. Meissner effect (flux exclusion) allows magnetic levitation of objects:

(A diagram of the Meissner effect and the Shanghai Maglev Train which works on this principle.)
Images taken from Wikimedia Commons. Meissner effect; Shanghai Maglev

3. Superconducting phase transition shows a sharp differentiation between conventional and superconductive states:
(Constant-volume specific heat and resistivity of a superconductor around the critical temperature.)
Image taken from Wikimedia Commons