Contrary to widespread belief, most data storage formats are quite durable. If properly maintained and kept in a controlled environment, magnetic or digital/optical audiovisual data can be accessed thousands of times without any perceptible loss of quality. However, replaying these files and accessing the data requires the necessary equipment to be in full working order. Even if the storage devices themselves (tapes, CDs, wax cylinders, DVDs, etc.) are in perfect working order, without the machine to read and play the data they are essentially worthless because they are inaccessible. Therefore, it is not always enough to simply preserve that data itself, organizations must also preserve all of the hardware that the data format requires.