Cocaine is also known as coke, charlie or snow. Crack, which is a kind of 'baked' version of cocaine can be called rock, stone and wash.
Cocaine comes as a white powder that is usually snorted up the nose.
Cocaine will give you a confidence 'buzz' for about 30 minutes. With crack the buzz is shorter but much stronger and more addictive, leaving you with a powerful craving for more. Cocaine can cause heart problems, convulsions and paranoia. Snorting it may permanently damage your nose. Smoking crack may also damage your lungs.