Truncation allows you to get more out of your search term.
Often times the databases do not understand plurals.
For example:
A search of DADA might give you 576 Results.
A search of DADAISM might give you 224 Results.
However a search of DADA* will give 814 Results.
Truncation Symbols Vary:
Library Catalog and Most Databases is: * (asterisk)
Lexis Nexus is: ! (Exclamation Point)