A file or folder name is a string used to identify a file. It can consist of 255 characters, including alphabetical letters, numbers, and special characters, excluding (/), which is used as the directory separator. You can include special characters (meta-characters); however, use of certain characters in filenames is not advisable, including ', ", $, #, !, and so on, because of their special interpretation by the shell.
Linux is case-sensitive as well as space-sensitive, so filenames are also case-sensitive. This means if we create files with the name data.txt and Data.txt in the same directory, then it results in two unique files.
The space is an acceptable character in Linux filenames; however, a space is also used as a delimiter by the command shell for command-line syntax interpretation, so it is generally not advised to use spaces in filenames in case this leads to ambiguity when executing commands.