This type represents what practitioners call a "yield curve", which in turn refers to the market available information about discount factors for all maturities.
Web blog example here The yield curve is almost always a prerequisite to derivatives pricing. Its purpose is to provide the market-implied discount factor for any requested maturity.
The input market rates must be supplied as objects of type Yield Curve Input as input to the key Market Data Note, there exist too many different variations of Yield Curve objects that can be created by using different combinations and types of such objects. For example, when swap rates alone are used as input, the produced Yield Curve object would typically look like Yield Curve Swaps
The extraction of discount factors is not uniquely determined by the market inputs. The discount factor is built for all possible times according to Build Method so that a certain mathematical quantity defined in Modelled Qty is interpolated according to Interp Method
In simple pricing contexts, a single Yield Curve suffices for providing the required discount factors. But in the presence of several currencies and floating rate indices, several curves may be needed that are distinguished from each other by their entries in the keys Currency and Issuer Deriscope will issue an error, if, in any pricing context, two curves are supplied that agree in both these two important keys because of the ensuing ambiguity in choosing one of these curves.