For example, candle and holder would generate a result set that contains both words. However, for candle or holder, the result set returned would contain both or either words.

For example, "candle holder" would generate a result set which matches the exact string.

For example, glass and (burner or bowl or "candle holder") would return a result set containing the combination of the first word "glass" and anyone of the other words: "burner" or "bowl" or "candle holder".