When you are thinking about growing Cannabis, you have to think about what kind of Cannabis you want to grow.
There is Indica, Sativa, Hybrid and Ruderalis.
Indica provides a strong body high which tends to be more relaxing to the user of the strain. Indica tends to grow shorter and has much rounder leaves. Sativa tends to give a strong mental or cerebral high to the user and grows much larger in height but has very skinny narrow leaves. A Hybrid strain has both the best characteristics from Indica and Sativa, so this is great for growing indoors. Indica is the easiest to grow indoors because it requires less light and grows so short which is great for confined spaces. Hybrids are great because of the Indica characteristics. Sativa is very challenging to grow indoors, but it still can be done. Typically if you want to grow Sativa indoors, you must train your plant to be suitable for indoor growing. This may require either tying the plant in certain way so most of the buds are able to keep a certain distance from the light, or you might need a metal mesh to keep the plants from growing all the way to the light. The metal mesh will allow the plants to spread around so that the buds are getting the ideal amount of light. Sativa strains are best grown outdoors as they get plenty of Sunlight and they will absolutely flourish as long as they have enough water and nutrients. Sativa plants can be grown as tall as trees and they grow very fast.