对话是什么，会话ID是什么

#include<iostream>
#include<windows.h>
#include<tchar.h>
#include<stdlib.h>
#include<windows.h>
using namespace std;
char source [] = "This is the source string";
char target [ sizeof(source) +1 ]={0};
void main()
{
    DWORD processID = ::GetCurrentProcessId();
    DWORD sessionID;
    if( ::ProcessIdToSessionId( processID, &sessionID) )
    {
        printf("Process '%u' runs in Terminal Services session '%u'",
            processID, sessionID);
    }
    else
    {
        printf("unable to get Terminal Services session ID for process '%u'",
            processID);
    }
    int a;
    cin>>a;
}