There are 3 types of reels:
Spincast: This type of reel has a closed face. All the important parts are kept inside, under the nose cone. The line comes out of a little hole in the cover. You see a lot outfits designed for children sporting this type of reel, because it is the easiest to use. To use a spincast reel, you press the button on the back of the reel during your forward cast. The line peels out, and you let go of the button the line stops. Its very easy to get the hang of this reel, but you sacrifice some accuracy and distance.
There is one more term you are going to run into around reels that you absolutely need to understand, and that is:
Drag: This is the mechanism that allows you to set how much resistance a fish feels when it pulls on the line. The tighter you set the drag, the more resistance the fish feels. You want to set the resistance tight enough that it tires out your fish, but not so tight that the line gets over stressed or breaks.