In C++, what is the benefit of using typedefs in a program? Here is an exmaple line of code: typedef double value_type; Does this mean that value_type therefore gets used throughout the program as a...

In C++, what is the benefit of using typedefs in a program? Here is an exmaple line of code:

typedef double value_type;

Does this mean that value_type therefore gets used throughout the program as a specified description for a double? Why can't we just use double always?