Some databases will allow the use of proximity or positional operators. This means you can locate one word within a certain distance of another. This is helpful when you don't want the preciseness of a phrase search but you also don't want the expansiveness of an AND search. Not all databases provide this option but if they do it can include:
The symbols generaly used include: n or w or adj.
The adj represents the word "adjacent"
The w represents the word "within"
The n represents the word "near"
Adjacent (ADJ) - terms in the search box must appear in the record next to (adjacent to) each other in the same order as you enter them.
Example: civil adj rights
Near operator (N/x) - finds words within x number of words from each other and usually it is regardless of the order in which they appear.
Example: ballistic n/3 missile
Within Operator (W/x) - finds words within x number of words from each other, and in the order they are entered
Example: biological w/5 terrorism
If you are a Google user you might want to consult this GoogleGuide on Search Operators to help you conduct better Google searches.
Must contain both
Must contain only
AND [narrows the search]