Boolean logic is a building block of many computer applications and is an important concept in database searching. Using the correct Boolean operator can make all the difference in a successful search.
There are three basic Boolean search commands: AND, OR and NOT.
AND searches find all of the search terms. For example, searching on dengue AND malaria AND zika returns only results that contain all three search terms. Very limited results.
If you're searching for a phrase rather than just a single word, you can group the words together with quotation marks. Searching on "dengue fever" will return only items with that exact phrase.
It's a lot like basic math. (2 × 4) + 1 = 9 but 2 × (4 + 1) = 10
Think of your search in concepts, then put those concepts inside parentheses. Different databases have different rules about combining searches. To make sure you get the search you want, use parentheses - every database follows those rules. For example:
dengue OR malaria AND zika can be interpreted as