* any word using the word trunk preceding an asterisk will be searched by the database, for example misinform, misinforms or misinformation. Most databases use this--it's called truncation.
" " the database will search the words inside the quotation marks as a bound phrase--the words must be side by side, usually in the same order. Most databases use this AND so does Google.
OR it's best to use only single keywords or bound phrases in each search box, unless there are synonyms or other alternate words that are acceptable, then they must be linked with OR.