Why should you sometimes truncate a word by leaving out a letter or group of letters (e. g., creat rather than create)?

Truncation is a method used in searching databases wherein the ending of the word is substituted with a symbol. Common symbols include an asterisk *, question mark ?, and dollar sign $. Truncation is used in order to broaden a search to include different forms of the truncated word. For example, the given word is "create".  When truncation is used, it becomes creat*. Search results would include creating, creation, creator, and etc.