What is the difference between generic and brand name drugs?

According to the US Food and Drug Administration (FDA), a generic drug is identical (or bioequivalent) to a brand name drug in dosage, safety, strength, quality, performance characteristics and intended use. FDA requires that generic and brand name drugs have the same active ingredients, but generics may have inactive ingredients not found in brand name drugs. These inactive ingredients may cause side effects in some patients. Some patients may also find that generic drugs may not be as effective for them as brand name drugs. Besides these differences in the patient experience with these two types of drugs, cost is a major difference. Generic drugs are typically sold at a noticeable discount compared to the brand name drug.