# Charts and visual results

Apps can present typed results as ordinary data or as charts. The App supplies
the measurements and calculations; chart metadata describes how to present
them. A chart does not add an analysis that the App never performed.

## Read the meaning before the shape

Check the title, units, legend, time range, and description. A missing value
is not automatically zero. A category label should identify the underlying
meaning rather than rely on color or position alone.

Use a full view when the preview is too small. Controls depend on the chart
and client capabilities. If a client cannot display a result as a chart, the
ordinary data view remains important for understanding the result.

## When authoring a chart

Prepare the data in the App, preserve semantic types, and supply localized
labels and descriptions. Choose the simplest chart that makes the comparison
clear. Check empty results, missing values, different locales, and a small
screen as well as the normal case.

The detailed contracts are the [2D chart reference](../reference/charts/2d.md)
and the [3D chart reference](../reference/charts/3d.md). The
[chart gallery](chart-gallery.md) shows captured examples, and
[Developing Apps](developing-apps.md#charts-in-2d-and-3d) shows a localized
chart with its source.

[All human guides](index.md)