Abstract data types
When we write application code, we don’t care how strings are represented: we just declare variables of type String, and manipulate them using String operations.
Similarly, we don’t care how sets are represented: we just declare variables of type Set, and manipulate them using Set operations.
An abstract data type is a data type whose representation is hidden from, and of no concern to, the application code.Examples: String, Set.
Abstract data types are an excellent way to design large programs.