CD-ROM Towers: Hold more than one drive in a chassis. The box includes CD-ROM and/or DVD-ROM drives, power supply, and door. Towers come in various sizes: 4, 7, 14, 21, 28 drive and larger. They are also available in rack configurations. The tower can be connected to a computer or directly to your network.  Network connected towers contain small, but powerful, thin servers. We sometimes refer to these as Tower/Servers.

Pros:
Towers are easy to install and use - especially if you get the network attached interface. They are fast, and everyone can share all the CDs or DVDs at virtually the same time. The tower appears as a server on the network, and each discs appears as folder. You don't use up drive letters. To install a disc you just insert it in one of the CD-ROM or DVD-ROM drives. To remove a disc simply push the eject button on the drive. This is a good choice if you have a small number of discs and you update them frequently.

Cons:
CD-ROM towers are more expensive then Tower of Changers and Hard Drive Caching systems (described later).

Tower of Changers: This is similar to a CD-ROM tower. It contains 5 disc CD-ROM changers instead of individual CD-ROM drives. For example, seven Nakamichi 5-disc changers provide a total capacity of 35 CDs, rather than seven CDs. Larger towers are available that hold up to 56 changers or 224 CDs. They can be connected to computers, but the most popular systems include the servers that attach them directly to the network.

Pros:
Tower of Changers cost less per CD than CD-ROM towers. It's very easy to change the CD discs.

Cons:
They are slower than CD-ROM towers. If two or more users try to access two different CDs in the same changer they will have to wait for the disc to swap. It takes about 8 seconds for the disc to change. There are no DVD-ROM changers available.

CD-ROM Jukebox: Holds a large number of discs, available to a relatively few simultaneous users. They connect to a network server or to the network. They are excellent for archiving data - using CD-writers, DV-R writers, or DVD-RAM drives. For example, the JVC MC-7000 or MC-8000 hold up to 600 discs. It can store over 5.6 TB of data. The total cost for this solution includes not only the jukebox, but a software driver and interface kit for your computer. Jukeboxes are available with CD-recorders, DVD-RAM drives or DVD-ROM readers.

Pros:
Excellent for data archiving. Jukeboxes are also good for some other special applications. They can be used for CD duplication and printing, and for large capacity data access.

Cons:
Expensive and slower than other systems. It is not the best for accessing data. A jukebox with six drives allows six users to access six different discs simultaneously. The next user has to wait (if someone wants to read a different disc).

Turbo Tower/Servers: These systems copy the CD or DVD discs to a hard drive and provide a very cost effective and high performance solution. Turbo tower/servers contain a powerful thin server. You can choose drives (for example 9, 18, 36 Gb or larger), and a choice of CD-ROM drives, DVD-ROM drives, CD-changers, or even CD-Recorders. They connect directly to an Ethernet 10/100 network hub.  Turbo towers can not be connected directly to a computer or server. They only connect to a network. This is really a disc appliance that makes it very easy to cache the discs to the hard drive. As soon as you insert the disc in the drive, the Turbo Tower automatically copies the content of the disc to the hard drive.  When the copying is completed, the disc is ejected. A web browser is used to set up and administer the unit.

Pros:
The Turbo tower provides a number of benefits including faster access time, faster data transfer rate, and lower cost per CD title (between 10 and 255 CDs).

Cons:
The down side is that it takes time to cache or copy the CD to the hard drive. Even though the process is very easy and automatic it still takes about about 3 minutes per CD to load the CDs for the first time.