Whenever I go into a dispensary and ask about various strains, the first thing every single bud tender mentions is whether the strain is indica, sativa, or hybrid. Most people who've heard of indica and sativa know that sativa's produce head highs and indica's give a more sedative experience. If you know this too, you're wrong. The difference between indica and sativa has absolutely nothing to do with feeling you get when you smoke it.
The actual difference between sativa and indica
The real difference between sativa and indica comes from the structure of the plant and the length of growing cycles. Sativa plants can grow very tall with long narrow leaves while indica plants never reach the same height and produce broader leaves. Sativa plants also require much longer flowering cycles, making them suited for dry and warm climates. Indica plants flower much faster and can handle cooler climates with shorter growing seasons.
Although interesting and significant for cultivators, these characteristics make no difference to the experience you feel when you consume it.
What should you be using instead of sativa vs indica
When you smoke a plant, you ingest chemicals produced by the plant. In the cannabis plants, the most important chemicals are called cannabinoids. Of many different cannabinoids, THC and CBD most impact the experience and feeling associated with a strain. THC takes responsibility for the head high while CBD produces many of the body effects and feelings of relaxation. THC acts a psychoactive chemical while CBD is anti-psychotic. The ratio between these two cannabinoids determines whether a strain will make you creative and energetic (high THC) or want to relax on the couch (high CBD).
Terpenes can also influence the experience but less is known and proven about their specific effects. Many plants other than cannabis produce terpenes and aromatherapy is basically the understanding and practice of using various terpenes. More study is need to prescribe specific terpenes but in general, terpene profile also plays a role in the experience.
Overall, please stop saying a strain is indica, sativa, or hybrid unless you're a grower. When you're looking for specifics about cannabis for your own needs, hopefully you can make a more informed decision and educate others as well.