Like most every other member of the Plant Kingdom, the Cannabis plant has a few different varieties that include Sativa, Indica, Hybrid or Ruderalis. You won't typically see a Ruderalis bud for sale in your local dispensary as they are mostly used by breeders for their autoflowering tendencies.
"Of India" discovered in India and cultivated for seeds, fiber, and making hashish, the plant grows shorter and bushier than Sativa. The Indica leaves are broad and dark green in colour.
The effects of Indica tend to be deep relaxation, sedation, reduce anxiety, increase appetite, decrease pain. A simple way to remember Indica's effect is:
In-di-ca = In da couch.
Originates from parts of Central Asia and cultivated for fiber, oil, food, recreation, religion, spiritual ceremony, and medicine. The Sativa plant grows taller and less bushy than it's Indica counterpart. The leaves are thin and serrated and the plant can grow up to 20 ft tall.
The effects of Sativa tend to be an increase in energy, creativity, reduces depression, increase appetite, decrease pain.
A Hybrid is a genetic mix of specific strains from both Indica and Sativa. A breeder will cross-pollinate specific breeds to create a new breed altogether. A successful Hybrid will have characteristics of both parent plants, you may get a quick boost of energy from the Sativa attributes and then get the strong sedation effects after.
Because the Cannabis plant has spent so much time on the black market, all the bud you get today will likely be a hybrid. There has been no solid documentation and classification of the plant over the years and as such there has been no adherence to keep specific strains "pure".
So you can see there are vast differences in the effects of each type of Cannabis which you can tailor to what works best for you. Education is this case is of utmost importance, because you could have adverse and undesirable effects if you do not have full understanding of what you are consuming.
Education is power, my friends.