understanding built-in variables

 #include<iostream>

using namespace std;

int main()

{

    int a=4,b=5;

    float pi=3.14;

    char c='a';

    cout<<"The value of a and b is:"<<a <<" and " <<b<<"\n";

    cout<<"The value of pi is:"<<pi<<"\n";

    cout<<"The value of character is:"<<c;

    return 0;

}