These are all types of speaker enclosures or boxes.
Enclosures exist solely for the purpose of accommodating the woofer.
Tweeters and midranges do not have to be enclosed at all, though they are often mounted in enclosures along with the woofer. To help you decide which type is best for your purposes, we offer a page containing detailed explanations and illustrations of each type, along with information on the types of materials used in their construction and a few suggestions. Read the instructions that came with your unit. They will usually identify the wires and their connections, as well as contain special instructions. This information may be on one of the unit covers as well.