However, they may have restrictions on the use of certain special characters, disallowing them within filenames; those characters might be used to indicate a device, device type, directory prefix, file path separator, or file type.File systems typically have directories (also called folders) which allow the user to group files into separate collections.This results in unused space when a file is not an exact multiple of the allocation unit, sometimes referred to as slack space.
A filename (or file name) is used to identify a storage location in the file system.
Most file systems have restrictions on the length of filenames.
As a file system is used, files are created, modified and deleted.
When a file is created the file system allocates space for the data.
By separating the data into pieces and giving each piece a name, the information is easily isolated and identified.; microsoft.support = microsoft.support