The notion of type is used to make programs more readable, make them run more efficient, and
to detect certain errors before they cause errors in the calculation.
Readability
Explicitly typed variables, parameters and function
serve as important documentation, which enhances the program understanding.
Efficiency
Knowledge of the properties of data makes it possible to generate more efficient code
Correctness
Explicit information about types in a program is a kind of redundancy against which it is
possible to check expressions and values
Programmers usually wish to identify type errors as early as possible in the development process
