If you wish to use the boolean search on multiple words, you need to use the special operators & [AND], | [OR], ~ [NOT]
For example, apple & orange will find all articles which contain both words. This gives the same result as Match All.
apple | orange will find articles containing either word. This gives the same result as Match Any.
apple ~ orange will find articles which contain apple but do not contain orange.
You can combine these operators; so using (apple & orange) ~ banana will find articles that contain both apple and orange, but not banana.