The**call chart** provides a graphical representation of a method trace or function trace, where the period and timing of a call is represented on the horizontal axis, and its callees are shown along the vertical axis. Calls to system APIs are shown in orange, calls to your app's own methods are shown in green, and calls to third-party APIs (including Java language APIs) are shown in blue. Figure 1 shows an example call chart and illustrates the concept of self time, children time, and total time for a given method or function. You can learn more about these concepts in[Top-down and bottom-up charts](https://developer.android.com/studio/profile/chart-glossary/top-bottom-charts).

![](https://developer.android.com/static/studio/images/profile/call_chart_1-2X.png)

**Figure 1.**An example call chart that illustrates self, children, and total time for method D.

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