The format of a file is defined by its content since a file is solely a container for data, although on some platforms the format is usually indicated by its filename extension, specifying the rules f...The format of a file is defined by its content since a file is solely a container for data, although on some platforms the format is usually indicated by its filename extension, specifying the rules for how the bytes must be organized and interpreted meaningfully. In this method, each block is assigned a number sequentially and the list of the numbers of all free blocks is maintained in a reserved block of the disk.