Unless something random seeds Rand. Rand will generate the same random numbers every time. In this case were using your computers time.
And every time you loop your system time is different So your numbers from say 3:43:01 to 3:43:02 will be different. Random enough for most applications.
Read Beginning C++ Game Programming
· ISBN-10: 1592002056
· ISBN-13: 978-1592002054
That’s where I learned that