All: Type multiple words (separated by spaces) in the Search for box, and the search will attempt to find documents that contain all of the words.

Any: Type multiple words (separated by spaces) in the Search for box, and the search will attempt to find documents that contain one or more of the words.

Boolean: Type multiple words as a logical expression (separated by AND, OR, NOT; grouped with parenthesis) in the Search for box, and the search will attempt to find documents that contain words that match your expression. For example:

To search for documents containing:	Type:
The word stars or the word  moon	stars OR moon
The word stars and the word moon	stars AND moon
The word stars but not the word moon	stars NOT moon
The word stars, or the words celestial and body	stars OR (celestial AND body)
The words moons and planets, but not the words stars and quasars	(moons AND planets) NOT (stars and quasars)