indicas have shorter, broader leaves and usually have thicker buds.. when smoked, indi's tend to give more of a couchlock, body type of high... indicas are usually grown in mountainous regions like afghanistan, ,morroco, nepal, etc... indica's are usually used to produce hash in these regions as well.. sativa's are much taller, lankier plants, they can take up to 14 weeks to flower as opposed to indi's much shorter times... the buds from sativas are usually not quite as tight as indi's are.. sativa's when smoked give more of a head high, more energetic.. a good example of a sativa is a haze... sativa;s are grown mostly in tropical regions, hawaii, india, jamica, mexico, south america... this is cuz these regions are the only ones that have a long enough warm period to allow these plants to flower long enough before frosts come.. its up to you on which strain you want to grow.. must indoor growers stick with indica or indica dom crosses as height is an issue a lot of times, a long with the preffered shorter flowering times..