Medicine is the study of prevention and treatment of disease. Medicines are substances which can come in various forms. Common medicines come in liquid, tablet, or capsule form. Tablets such as the contraceptive pill can also be used for daily prevention. Tablets can also be found in the form of pain killers such as paracetamol and ibuprofen. There are also specialized cancer medicines. Topical medicines are applied directly to skin, medicine drops are used in eye, ears or noses, inhalers are breathed into the lungs and injections often provide immunity by injection into a vein.