This chapter discusses various ways to juggle basic data types in Haskell. A data type is something like a number or a character of the English alphabet. When you have a sequence of characters, you get a data type called a string because you are stringing together a bunch of characters in a given order. You will learn about another data type called boolean, whose only values are either true or false. Numbers, strings, and booleans are among the most fundamental building blocks upon which you construct programs. Lists are another important data type you will meet again and again throughout your journey of learning Haskell.