Topics such as that are covered very well in many books and tutorials. You can get more complete answers using those.
If you don't know what use a static type is, then you probably don't need it. It would be better if you were to have a specific requirement and then ask what the solution is.
A static type could be used for a variable that is local to a function but is not initialized each time the function is called. A non-static type does not retain a previous value from the previous execution of the function whereas a static type changes only when you change it explicitly in code. A static type could be used in places that a global might be used.
Of course, genral questions such as yours are often asked as homework, in which case it would be better to not answer it for you. It would be more educational for you, even if this is not a question to be turned in for a grade, if you were to read the documentation and then ask specific questions based on what you read.