On this tab, you can see a list of search indexes. Search indexes store data about the content of your website in order to facilitate searching of the site using the Smart Search module. If there is a large amount of displayed search indexes, you can filter them by their Display name using the filter above the list.
You can create a new index by clicking the New index link.
You can edit properties of the indexes in the list by clicking the Edit () icon. You can also delete a listed index by clicking the Delete () icon.
By clicking the Rebuild () icon, you can rebuild the selected index. If you choose to rebuild an index, the original index is removed and all the specified content gets indexed again. Clicking this icon does not always guarantee that the index will be rebuilt immediately. The process may be delayed if e.g. another index is already being rebuilt or if the rebuilding tasks are configured to be handled by the scheduler.
More resources can be found at Developer's Guide -> Modules -> Smart search -> Overview.