Historically, a course on data structures has been a mainstay of most computer science departments. Over the last 18 years, however, the focus of this course has broadened considerably. The topic of data structures has now been subsumed under the broader topic of abstract data types (ADTs)—the study of classes of objects whose logical behavior is defined by a set of values and a set of operations. The term abstract data type describes a comprehensive collection of data values and operations; the term data structures refers to the study of data and how to represent data objects within a program; that is, the implementation of structured relationships. The.