Sam is right, sometimes the best way to learn is to just "roll your sleaves up" and get your hands dirty with some code. Examine the behaviour and see what its doing. You are then in a position to either understand why, or not. If you do, great, if not, then forums are an ideal place to ask "Why" rather than "What".
Put simply, the answer to this question is obvious is you have an understanding of the fundamentals of Object-Orientated programming.
Follow Sam's advice, play with some code, see the results, find out why it does what it does! A lot of the fun of coding comes from discovery!
The Developing Developer
Currently Working Towards: MCAD C#
My Blog: http://www.robzyc.spaces.live.com
<center>"Nothing can stop the man with the right mental attitude from achieving his goal;
nothing on earth can help the man with the wrong mental attitude".