Illegal drugs are put into three different classes in the UK - A, B, and C.
Class A drugs are considered to be the most harmful and attract the most serious punishments and fines.
Class A drugs
These include heroin, cocaine, ecstasy and LSD.
If found guilty by a court of law of possessing Class A drugs you could go to prison for up to seven years and fined.
If you sell Class A drugs you could receive a life imprisonment.
Class B drugs
These include amphetamines, such as speed and barbiturates, and cannabis.
People found guilty of possessing a Class B drug could go to jail for up to five years and be fined.
Those caught and found guilty of trafficking a Class B drug can be sent to prison for up to 14 years.
Some people think having cannabis is less serious than other drugs, but if you're caught with cannabis the police will always take action.
Class C drugs
Drugs in this category include, tranquillisers, valium and anabolic steroids.
It is illegal to have, give away or deal in Class C drugs.
Maximum penalties for possession are two years in jail plus an unlimited fine.
Dealing or supplying could get you 14 years in jail plus an unlimited fine.