Typedef is used to explicitly define new data type names by using the keyword typedef. It defines a name for an existing data type but doesn't create a new data type.
Typedefs helps in portability as you can just change the typedefs alone when you move from one system to another.
Syntax
typedef data-type name;
Example
#include <iostream>
using namespace std;
int main()
{
typedef unsigned int distance; // typedef of int
distance d1;
d1 = 150;
cout << "Distance is: " << d1;
return 0;
}