Generic vs. brand-name drugs
Generic versions usually aren't available for the newest drugs on the market. New medicines must go through an approval process with the Federal Drug Administration (FDA). Once a new drug is approved, it is granted exclusive marketing rights for a set number of years. This is what is often referred to as a brand-named drug.
Generic drugs are those that have been approved by the FDA but no longer have the exclusive marketing rights granted by the approval process. Their chemical formulas are in the public domain and any drug manufacturer can sell them. Because there's more competition among suppliers of a generic drug, prices are almost always lower.
Note: If your doctor writes you a prescription for a brand-name drug, your pharmacist can't substitute a lower-priced generic unless the prescription specifically allows for substitution. Asking your doctor to allow substitutions could save you money.