A Chart.js chart is created using a configuration object that controls every aspect of the chart. This configuration object is passed to the Chart.js constructor and contains three main properties: type, data, and options.

The type property specifies the kind of chart you want to render, such as 'bar', 'line', 'pie', or others. Choosing the correct type is essential because it determines how your data will be visualized.

The data property defines the information that will be displayed in the chart. Inside data, you provide labels, which are the categories or points along the axis (for example, color names), and datasets, which is an array of objects. Each dataset object includes a label for the dataset, an array of data values, and styling options like backgroundColor and borderColor.

The options property allows you to customize the chart's appearance and behavior. This can include settings for axes, legends, tooltips, and more. In the configuration above, the options object sets the y-axis to begin at zero, which is a common requirement for bar charts to ensure accurate visual comparison.

Together, these three properties make up the full configuration for a Chart.js chart, giving you control over what is displayed and how it looks.