The name of a file, excluding root drive and directory path information. Different operating systems may impose different restrictions on filenames, for example, by prohibiting use of certain characters in a filename or imposing a limit on the length of a filename. The filename extension should indicate what type of file it is. However, users often change filename extensions to evade firewall restrictions or for other reasons. Therefore, file types must be identified at a binary level rather than relying on file extensions. See also File Extension and Full Path..”