std::string 是什么

#include "stdafx.h"
#include <iostream>
#include <string>
using std::cout;
using std::endl;
using std::cin;
using std::string;
int main(void)
{
    char chars1[20];
    char chars2[20] = "jaguar";
    string str1;
    string str2 = "pather";
    cout << "Enter a kind of feline: " << endl;
    cin >> chars1;
    cout << "Enter another kind of feline: " << endl;
    cin >> str1;
    cin.get();
    return 0;
}