Truncation uses a symbol to account for variations of a word. The database will find records containing words beginning with the portion of the word you provide. You need to use this carefully, though, because it can result in false “hits”
Example: theat* will give you records containing the words theater, theatre, theaters, theatres, and theatrical; scen* will give you records containing the words scene and scenery but also scenic and scent. Note that the truncation symbol varies from database to database. Most use an asterisk but a few use an exclamation mark, a percentage mark or a question mark. The description of the database (found by clicking on the “i” in the blue dot next to the database name) identifies the symbol used.