An asterisk (*) may be used to specify any number of characters. It is typically used at the end of a root word, when it is referred to as "truncation." This is great when you want to search for variable endings of a root word.
For example: searching for educat* would tell the database to look for all possible endings to that root. Results will include educate, educated, education, educational or educator.
A question mark (?) may be used to represent a single character, anywhere in the word. It is most useful when there are variable spellings for a word, and you want to search for all variants at once.
For example, searching for colo?r would return both color and colour.
