An index can essentially be considered a database that contains all of your searchable content. By default, it will store everything in a field called `Content`, which is queried to find your search results. To create an index that you can query, you can define it like so:
```php
use Page;
use SilverStripe\FullTextSearch\Solr\SolrIndex;
class MyIndex extends SolrIndex
{
public function init()
{
$this->addClass(Page::class);
$this->addFulltextField('Title');
}
}
```
This will create a new `SolrIndex` called `MyIndex`, and it will store the `Title` field on all `Pages` for searching.
You can also skip listing all searchable fields, and have the index figure it out automatically via `addAllFulltextFields()`. This will add any database fields that are `instanceof DBString` to the index. Use this with caution, however, as you may inadvertently return sensitive information - it is often safer to declare your fields explicitly.
