Contrary to hemp, marijuana contains larger levels of THC, more than 30% THC, making this plant more potent for creating the high associated with marijuana use.
The THC concentration in marijuana is certainly enough to cause a high, so it is often used recreationally. It is also used for several medicinal purposes in different states where its consumption is legal.
There are many species of marijuana, such as indica, sativa and ruderalis varieties. Each strain of marijuana has its own effects. These are commonly referred to as indica-dominant, sativa-dominant or ruderalis dominant. On the other hand, hemp is always Cannabis sativa, while marijuana has much greater variation. There are about 800 marijuana strains, but hemp is only ever Cannabis sativa.