Chances are your favorite tv show has a trading card set.  Or maybe you're just looking to buy cards as a present for someone.  But how do you know what to buy? There are sets, boxes.... it can be confusing to those who aren't familiar with trading cards.  Here's a brief overview on what the various terms mean.

Unopened card Boxes. Trading cards come in boxes.  Each box contains a certain number of packs.  Each pack contains a random assortment of base cards and may contain a special card (such as an autograph or costume card).  Once you open all the packs you should (depending on the manufacturer) get at least 1 of each basic card and some special cards.   You will also have (in most cases) lots of extra cards left over.    If you are buying a box (produced 2000 - present) for someone make sure that you are buying a FACTORY SEALED box.  99% of the entertainment cards come sealed in shrinkwrap from the manufacturer.  Make sure that's what you are buying as there are some people out there who will open packs until they find the autograph or costume card and then reseal the box and sell it.   Also keep in mind that this is a recent trend. Sealed boxes and special cards didn't really come around until the late 1990's - early 2000's.  Boxes produced prior to then didn't come in shrinkwrap.

Basic cards. Basic card sets are just that.  They usually contain cards for each character (assuming we're talking about entertainment cards), cards for each episode (or scenes from the movie) and maybe some behind the scenes cards.  If you want to buy a present for someone who likes Harry Potter buy them a set of basic cards and chances are they'll be pretty happy.

Special or Chase Cards.  These can be anything from foil cards to autograph or costume cards.  These are not included with a basic card set as they are harder to get.  In a box of cards you may only get 6-8 special cards, making them more valueable (and expensive) then basic cards.