Would you mind explaining or comparing an AND search and/to an OR search, please?
A google search would return all documents that contain John OR Jacob OR Jingleheimer OR Smith.
In other words, adding search terms in an AND search narrows down the pile of results to closer and closer to what you actually want.
In a google search, the pile gets deeper and deeper every time you add a word to the narrow the search.
The google hep people I've talked to blandly assure me that this is an AND search - You get every document that has the word John, and every document that has the word Jacob, and every document that has the word Jingleheimer and...