Cannabis is a drug that comes from the cannabis sativa plant. Traces of THC can remain detectable in blood samples for days, even weeks, after use. Like alcohol, cannabis is a 'depressant' drug. Depressant drugs do not necessarily make you feel depressed, Rather, they slow down the central nervous system. They slow down the messages going to and from the brain to the body.
Cannabis also has mild hallucinogenic effects.
It is the most common and least powerful form of cannabis. Is small blocks of dried cannabis resin. Blocks are usually brown or black. The concentration of THC in hashish is higher than in marijuana, producing stronger effects. Hash is added to tobacco and smoked, or baked and eaten in foods such as hash cookies.