Heterogeneous is an adjective used to describe an object or system consisting of multiple items having a large number of structural variations. It is the opposite of homogeneous, which means that an object or system consists of multiple identical items.
In the world of enterprise computing, heterogeneous data is a mix of data from two or more sources, often of two or more formats, e.g., SQL and XML. Distributed systems are called heterogeneous if they contain many different types of hardware and software. heterogeneity of the system means the ability of that system to work with different systems