A typedef declaration lets you define your own identifiers that can be used in place of type specifiers such as int, float, and double. A typedef declaration does not reserve storage. The names you define using typedef are not new data types, but synonyms for the data types or combinations of data types they represent.
The namespace for a typedef name is the same as other identifiers. The exception to this rule is if the typedef name specifies a variably modified type. In this case, it has block scope.
When an object is defined using a typedef identifier, the properties of the defined object are exactly the same as if the object were defined by explicitly listing the data type associated with the identifier.
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