To explain what this means, we will use an analogy involving a very large file cabinet. Every drawer of this cabinet can contain only one file. If it fills the drawer, you are using the drawer efficiently. However, if you just put several sheets of paper into that drawer, you will waste tremendous amounts of space. Computer files can span several clusters, with the wasted space 'living' in the last cluster occupied.
Cluster size is determined by the size of the hard drive.
Use the table shown in Table 14 to see where you stand on wasting space when using the FAT file system. Let us assume the following. We have a computer with a 1.2 GB hard drive. Storing a 8 KB file in a 16 KB cluster improves your storage situation by percent. Now you are wasting only 50 percent of a cluster.