Some computer cases use plastic or metal rails that are secured to the sides of a drive so it can slide
into the bay in the chassis. Other case designs have drive bays that directly accept the drive via screws
through the side supports, and no other hardware is necessary. Some cases have tool-free designs with
sliding latches to secure drives without screws. Still others use a cage arrangement in which you first
install the drives into a cage and then slide the cage into the case (see Figure 19.28). If your case uses
rails or a cage, these are usually included with the case. With the proper mounting mechanism supplied
via the case, all you need is the bare drive to install