Marijuana is a commonly used alternative term for cannabis. Marijuana is actually a common term that can be used for seeds, stems, flowers or leaves derived from the plant, Cannabis sativa. It contains some strong chemicals that can influence mind and act as the mood lifter. The most important chemical found in marijuana that affects mind and body is 9-tetrahydrocannabinol (THC). 
Marijuana is a commonly used drug in different parts of the world but its cases are significantly higher in the United States. It is particularly common among the youths below 20 years of age. There has been a significant rise in the usage of marijuana among students studying in middle and high school in the last few years. The states and the federal laws are strict in most of the states against the usage of marijuana for recreational purposes. But the citizens or the people of the United States, especially youngsters are pushing hard to legalize possession and distribution of marijuana for all purposes.
Some of the states have already legalized usage of this illicit weed for medical usage but the number of states that have allowed it to be used for recreational purposes is restricted to just four out of 50 states. If we go into the details of which states have legalized weed, we just have Alaska, Washington, Colorado, and Oregon. While people in other states continue to fight for legalization of marijuana, 20 other allow it to be used for medical purposes.
Experts are divided in their views about the extent of medical and industrial usage of marijuana. There is no doubt that it has harmful effects on the body which is the main reasons why its usage is restricted in most of the other states. However, the growing support of the people for the legalization of marijuana usage can change the scenario very quickly.