How do you use wildcards (globbing) in Linux?

Shell wildcards (globs) expand to match filenames. * matches any sequence of characters (except leading dots): ls *.txt lists all .txt files. ? matches any single character: ls file?.txt matches file1.txt, fileA.txt. [abc] matches any one character in the set: ls [abc]*.sh. [0-9] matches any digit. {jpg,png,gif} is brace expansion (not globbing) matching listed alternatives: cp *.{jpg,png} /backup/. Globbing is done by the shell before passing arguments to commands. Use quotes to prevent glob expansion when passing patterns to tools like find or grep.