Wildcard Abuse

A wildcard character can be used as a replacement for other characters and are interpreted by the shell before other actions. Examples of wild cards include:

Character	Significance
*	An asterisk that can match any number of characters in a file name.
?	Matches a single character.
[ ]	Brackets enclose characters and can match any single one at the defined position.
~	A tilde at the beginning expands to the name of the user home directory or can have another username appended to refer to that user's home directory.
-	A hyphen within brackets will denote a range of characters.

• See here and here for examples of wildcard abuse