File wildcards are special characters that represent one or more other characters in filenames, enabling pattern-based matching during renaming operations. The asterisk (*) represents any sequence of characters, while the question mark (?) represents a single character. Unlike a specific file rename, wildcards let you select groups of files sharing a pattern—such as files starting with "invoice" or ending in ".txt"—for simultaneous renaming.

For instance, in a Windows Command Prompt or Linux terminal, you might use ren project*.txt *_backup.txt to change all .txt files starting with "project" to have names ending in "_backup.txt". Similarly, GUI tools like file managers (Explorer, Finder, Nautilus) often let you select files like "vacation_photo?.jpg" to rename multiple images (e.g., "vacation_photo1.jpg", "photo2.jpg") at once by replacing parts of their names.

Wildcards offer speed and efficiency for bulk renaming tasks. However, they have limitations: they cannot perform complex pattern substitutions (e.g., inserting dates in specific positions) and rely solely on filename patterns, which can sometimes match unintended files. For highly customized renaming, specialized batch renaming tools or scripting languages (like PowerShell, Python with os.rename) using regular expressions offer greater flexibility.