Definition - What does Wildcard Character mean?
A wildcard character is a character that can be substituted for either a single character or a string of characters. For instance, in certain operating systems, the asterisk character "*" can be used in lieu of a set of characters, while the character "?" can be used in lieu of a single character.
Techopedia explains Wildcard Character
Wildcard characters, which can be used in SQL and other computer languages, can shorten commands by including a wide range of items without having to mention every single item covered by the command. One scenario that calls for usage of a wildcard character is when you want to search for a set of similar filenames at a Windows command prompt. To display specific files (such as notepad.exe or taskman.exe) in a directory, you type: "dir notepad.exe" or "taskman.exe." However, if you want to display all files with the ".exe" extension in the directory, then you simply need to type "dir *.exe."