Vector icon format for Android 8.0 Oreo and newer consisting of a foreground vector icon, and/or a background vector drawing and a mask for the overall shape provided by the specific Android configuration/style.
The idea, as with vector icons in general, is to reduce the need for multiple images for different combinations of Android versions and device screen resolutions. Also, the mask allows vendors to apply a style to all icons (for instance square, rounded square, circular) if desired.
Introduced with android-8.0-oreo as an xml format with an <adaptive-icon> tag in which <background> and <foreground> tags can be nested, each with an android:drawable attribute.
See also the Android developer page.
