The other name for marijuana is Cannabis. Marijuana is also known as ganja and marihuana in some countries. This particular drug is used by people purposely for its psychoactive effect normally belonging to the abuse category. The preparations of marijuana related drug stuffs in general vary from one country to another. Though it is a drug that has severe bad effects when crossed its usage limits, many countries have made its selling a legal while some still prohibit the usage or selling of marijuana. It is also estimated to be the most commonly used substance of illicit category. Every single part of a marijuana plant is employed in its drug preparation. The typical parts of this herb that find its place more commonly in the preparation of the substance include flowers, stalks and leaves. Usually the stalks of female plants that have matured are used in drug preparation. The resinous type of preparation is called as hashish or hash. Δ9-tetrahydrocannabinol or THC is the primary psychoactive chemical substance that is present in cannabis. The plant of marijuana is also found to be available in around 66 varieties. The other cannabinoids that are common today include cannabinol, cannabidiol and THCV or tetrahydrocannabivarin. Persons who use cannabis usually use a vaporizer to inhale the active substance. Use of vaporizers is more common today as it prevents the inhalation of irritating substances like tar present in the drug.