What is a medicine and explain two important of medicine

Medicine is the science or practice of the diagnosis, treatment, and prevention of disease (in technical use often taken to exclude surgery).

Two things make a drug important: First, that the drug is or was used to treat a large number of people with a range of problems

And second, because a drug has led the way, showing it is possible to treat a disease. These drugs spurred the pharmaceutical industry to further research and innovation. If you don't have a starting drug, you don't know what is possible -- and you can't take it on from there.