The Search API module by itself doesn't provide a UI for submitting a search query, or a page for displaying results. Instead, it exposes an API that other modules can use to provide those features. This makes it super flexible, but it also means we've got some extra work to do in order to allow someone to actually perform a search and see the results.
In this tutorial we'll look at using the Search API Pages module to create a simple search page with a form at the top and a list of results ordered by relevancy. Search API Pages is the quickest and easiest way to replace the Drupal core search module's functionality with a form that uses Solr for a search backend instead of MySQL.
When creating a new page with the Search API Pages module we can choose the view mode that we would like to use for displaying results. It works very nicely with Drupal's built-in view modes, as well as contributed modules like Display Suite, in order to allow for a high level of customization of view modes, and thus of the displayed results.
You can also configure the query type to use, choosing from one of: multiple terms, single term, or direct query. For integration with Solr you'll likely want to choose direct query, and allow Solr to handle the query parsing since it has a lot of advanced options that go far beyond what Search API handles on its own. However, we'll look at the different query type configurations, and demonstrate things we can do with direct query searches and the powerful Solr query syntax that we can't do with the other modes.
Finally, we'll look at the block that Search API Pages provides, and use it to replace the search form on the home page of our site with a form that points to our new Search API Pages search results page.
By the end of this tutorial you should be able to expose a page on your site that will allow your visitors to perform a search using the Solr index and have the results displayed in Drupal.