Lets be honest, the WordPress search is not that good. It’s based on keywords and displayed in reverse chronological order. It works, but it’s not very helpful. That’s where Relevanssi comes in.
Relevanssi replaces WordPress’ search and returns results based on relevancy.
Relevanssi also allows users to search with multiple words and it only returns posts that contain ALL those words. Why does WordPress not do this by default?!
If you want a better WordPress search, install Relevanssi.