Brand name drugs are the original drug. generics are almost the same as the brand name medication, the only difference lies in binders or what holds the drug together. some binders do not allow the medication to dissolve in the stomach, but instead in the liver or intestines. this means the medication may be less effective, than the brand name.

Some medications have to be completely identical as the brand name. these are mainly antibiotics and blood pressure medication.

No doubt, buying generics is very less expensive than the brand name. like i said, it depends on the medication. pain medications are a good example of drugs that can dissolve elsewhere, other than the stomach. this means a longer waiting period for pain relief.

One bares the brand name and the other does not and one costs a lot more than the other. Other than this, there is no significant difference. Both the name brand and generic drugs have to meet the same FDA standards with respect to manufacturing and formulation.

The brand name is the name under which a new innovator medication is developed and marketed. When a pharmaceutical company develops a new medication, they obtain patent for it. Brands are usually given patent protection for about 20 years.

When the patent of a brand-name drug expires, other companies can introduce its generic version. Generic drugs are identical or within an acceptable bioequivalent range to the brand name counterpart with respect to pharmacokinetic and pharmacodynamic properties(identical in dose, strength, route of administration, safety, efficacy, and intended use)
for example:
Diazepam" is an example of the chemical (generic) name of a sedative. It is marketed by some companies under its generic name such as Valium or Vazepam.