There are five different types of Cannabis: Indica, Sativa, Haze, Indica Hybrid and Indica Cross. Each has its own effect on the body and they can be classified according to how they affect you and also according to how fast you should expect them to take effect.
This is the type that comes from the Sativa plant. It has many of the same qualities of the different Indicas but has a slightly different high effect on the body. The Cannabis Haze comes from the two strains of Indica that have been hybridized together, resulting in a new plant that produces a little more THC than the other, which gives it a totally different effect.
The third one is called the Sativa, which is closely related to the Marijuana plant, being cross between the two. In this case, there are more body heaviness, more body tension, and pain for instance.
The Sativa is the fastest-growing Cannabis plant and thus more popular amongst those who want a quick high, it is also more suited to indoor cultivation and easier to grow. You can also get it from the same plant, or from any of the hybrids it has produced.
The other varieties are those that are not exactly crossbred and the other two types, the Indica and the Sativa come from two plants that have been crossed together, resulting in one that produces a THC level that is higher than the other, which gives it a more overpowering effect. These are often used in mass production of strains and make large amounts of money.
Some people like the High THC content of the Sativa, while others find the taste of the Indica more appealing. Both types produce about the same effect, but the results will vary, depending on how fast you are likely to take effect and the amount of THC your body is capable of tolerating.
Some grow them to have a constant high, but others like to have a low of Buds which are for personal use only. Most people find their best effect when using the more potent strains.
The main types of Cannabis are medical weed, which is high in THC and are typically used as a medicine, and recreational, which usually means higher THC. Medical cannabis is highly addictive and is only for long term use, while recreational is usually only a good recreational drug for giving a temporary high.
Many who grow them see them as big business, as not many people know what each plant has to offer. The one strain that is most sought after is the All Day Blues, as this has all the major effects of all the others and is the best in almost every way.
There are even a few Indians who make their living by growing Marijuana. They get their strains from America or from India and many of them travel to Europe to meet the buyers.
It is predicted that many new strains will be developed, and thus we will need many more people to grow these and keep an eye out for new strains. The long term effects of these strains cannot be predicted, so you may be in for a surprise at the end of the day.