Generic Drug Identifier

What is a Generic Drug anyway?
Generic drugs are the drugs which are manufactured and marketed without a patent. When a company produces a drug, it gets a patent to reserve its exclusive right to manufacture and market the drug. Every patent is granted for time period of 20 years. When the patent expires, the company loses the exclusive rights to produce and sell the drug and hence other companies get the approval to produce the off-patent drug. These off-patent drugs are known as generic drugs. Not all off-patent drugs are manufactured as generic drugs.