Although marijuana can have similarities between certain strains, the difference between indica and sativa is apparent in more ways than one. Whether it's the way it looks, smells, or the way it makes you feel, indica and sativa have differences that are easy to notice for those with experience, and might be more difficult to notice for marijuana novices.
Taking into consideration, the acceptance and use of medical marijuana in today's culture, these differences shouldn't be ignored, but utilized. The worst thing we can do is to treat marijuana as simply a means to get "high", completely disregarding the medical properties and the varying degrees that the plant can be used.
This infographic gives the most basic differences between indica and sativa, and is intended for medical and recreational users in states where marijuana is legal. As with any substance, not everyone has the same reaction, and the only real way to find out which strain is best for you, is to try it for yourself.