# JS API Reference

# Welcome to the Highcharts JS Options Reference

These pages outline the chart configuration options, and the methods and properties of Highcharts objects.

Feel free to search this API through the search bar or the navigation tree in the sidebar.

# drilldown.series

An array of series configurations for the drill down. Each series configuration uses the same syntax as the series option set. These drilldown series are hidden by default. The drilldown series is linked to the parent series' point by its `id`.