How do I create relevant keyword search?
You would need Search API and Search API Solr for this, along with a Solr instance to get relevancy scoring and support for fuzzy searching (e.g. iphone iphane etc).


https://www.drupal.org/project/search_api
https://www.drupal.org/project/search_api_solr


It is mostly configurable from the Drupal UI.