Although most generics are for drugs no longer under patent protection this is not always the case. A more accurate definition of a generic is the one from Wiki

Although most generics are for drugs no longer under patent protection this is not always the case. A more accurate definition of a generic is the one from Wikipedia, "A generic drug is a pharmaceutical drug that is equivalent to a brand-name product in dosage, strength, route of administration, quality, performance and intended use, but does not carry the brand name. The generic drug may differ from the original in non-essential characteristics such as color, taste and packaging."