Carpets are thin blocks used for decoration. They can be placed on any block, and sneaking (default LeftShift) can place Carpet on blocks you normally cant place on. carpet is very useful, as before 1.6 players had to use wool as carpet, and it got a bit anoying having to do the upstairs rooms floor wool, making the downstairs roof wool. If you put carpet on a fence, you can climb over the fence. Carpets are both items; as they are only 1/16 of a block, and a block; since they cannot be walked through and can be placed on anything.