Case sensitivity : Words or phrases with one or more upper case characters are treated as case sensitive. This means that searching for "lotus" will match any occurence of 'lotus' regardless of each letters case. This would not be true of a search for "Lotus".
Asterisk : The atserisk is used as a wildcard when searching. A search for t* will return all occurences of words beginning with "t" or "T" (remember the case sensitive rules;). A search on "de*s" will return all occurences of words beginning with "de" and ending with "s", such as Demonstrations!. The asterisks tool is extremely useful if you are not sure how to spell the term you wish to search for.
REMEMBER: The more detailed your query, the more relevant your results.