One major promise that comes with the completion of the Human Genome Project is that scientists and physicians will better understand the true cause of diseases. In some sense, knowing the genetics of disease is the single best hope for a cure. Surgery to remove a diseased gall bladder is a cure. It's a one-time affair that eliminates gall bladder problems for good. These kinds of cures are rare, but obviously desirable.
Surgery can remove or repair a problem, but in some cases the problem can recur.
Likewise, an antibiotic for strep throat can cure the disease. Although strep throat can re-occur, the antibiotic has the power to cure. Much more common is the situation in which a medicine takes care of the disease but does not cure it. Insulin injections take care of problems associated with diabetes, but insulin does not cure the disease. In that example, insulin is needed every day.