Indicas are notably squatter with fat 'paddle' leaves and more crystals/trichomes while Sativa is taller and thinner with leaves like the Cryptkeeper's fingers and with its crystals/trichomes kept more in the core. Indicas are much more heavier producers than sativas. The high is more of a body stoned effect versus a more clear soaring cerebral high from sativa. Indicas are easier to grow and Sativas are more difficult to grow but in my opinion more than worth it. Some sativa strains produce THCV, something not found in other sativas and not found in indicas, and it is THCV that makes some sativa a true rocket-sled ride.
Those are some of the difference.
