charts is a collection of chart options that allows you to set data and all attributes / properties of Charts to be displayed inside the StockChart. A Chart is created for each chart options object that you add to this array.
var stockChart = new CanvasJS.StockChart("container", { . . charts: [ {// chart options 1 }, {// chart options 2 } }], . . }); stockChart.render();
Please refer to chart options page for more information about the attributes / properties available.
Also See: