It is not a rudimentary question at all. It is actually a bit complicated to explain but I'll try (and hopefully a DVC veteran will come along and explain it better than I can!)
When you purchase DVC directly from Disney you will get "current year" points. For those purchasing DVC in 2006, your "current year" points will be either 2005 points or 2006 points depending on the use year of the contract you purchase, and the date you make your purchase.
For example, let's say in Feb 2006 you purchase a contract with an October use year. In this case you will get 2005 points because those are your "current year" points -- your 2005 use year began on Oct 1, 2005 and runs until Sep 30, 2006.
Another example: Let's say in April 2006 you purchase a contract with a February use year. In this case you are already in your 2006 use year (Feb 1, 2006 - Jan 31, 2007) so you would not get 2005 points. Your "current year" is 2006, so your first points are 2006 points.
Now as to whether or not you can bank them, that depends on where you are in your use year. At any time during the first 6 months of your use year you can bank 100% of your current-year points into the next use year. So going back to my first example, if you close on an Oct use year contract in February, you are within the first 6 months of your use year so you can bank all of your current-year points into your next use year. If you closed on that same Oct use year contract in Sep 2006, they probably would not let you bank any of the points because you are in the last month of your use year and you would have one month to "use 'em or lose 'em".
If you do receive 2005 points and are able to bank them, you get one additional year in which to use them. So if you purchased an Oct use year contract in Feb '06, you would receive, and could bank, your '05 points. Once banked, they can be used for stays between Oct 1, 2006 and Sep 30, 2007, along with your 2006 use year points which are valid during the same time period. Once banked, those Oct 2005 points will expire on Sep 30, 2007. They cannot be banked again. If you needed even more points for a stay between Oct 1, 2006 and Sep 30, 2007, you could also borrow points from your 2007 use year.
I hope this makes sense!