Soft Sleeves These are inexpensive and are good to use. They are just a little clear plastic sleeve that you slide your card into.
Top-loaders These are a little larger than the soft sleeves. Top loaders are made out of a semi-ridged plastic. Most people will put a soft sleeve on a card first and then put it into the top-loader.
Storage boxes These are specially designed boxes to put your cards in. They come in many different sizes. Some of the boxes are designed to put the top-loaders in and some are designed for the cards by themselves or in a soft sleeve.
Screw-down cases These are sturdy hard plastic cases that are usually reserved for your most valuable cards. Its a two piece case that is screwed together once your card is set in place.
Albums and pages These are like photo albums. You can get special plastic pages with slots in them for your cards 9 to a page. Albums are a bit more expensive but they are a great way to show off your favorite set or cards.