Search logics explained
The logic on the same or across the separate fields for each keyword (title, content, excerpt etc..)
Match is found if any of the search keywords is part of the content. It's the least strict of all possible options - it returns many results, finds almost anything.
Similar to the simple OR, but at least one keyword must match a whole word. Partial results are not accepted.
Every keyword must match at least partially the content.
The most strict search logic. Every keyword must match a whole word in the content.