Thread: What does this code means?

I have no idea what does this code means even though the book explained it. I think maybe it didn't explain well enough. Can anyone tell me what does this code means?

Code:

//This programme shows an example of using an if statement to check for no input
#include <iostream>
#include <string>

int main()
{
    using namespace std;

    char response[256];

    cout<< "What is your name? ";
    cin.getline(response,256);

    if (strlen(response) == 0)
    cout<< "You must tell me your name...";
    else
    cout<< "It's nice to meet you, "<< response;

    return 0;
}

I also have no idea about the char 256 thing =,=