The ability to distinguish, differentiate and contrast between different datasets is a key objective in data mining. Such an ability can assist domain experts to understand their data, and can help in building classification models. His presentation will introduce the principal techniques for contrasting different types of data, covering the main dataset varieties such as relational, sequence, and graph forms of data, clusters, as well as data cubes. It will also focus on some important real world application areas that illustrate how mining contrasts is advantageous.