Q:

What is XML-like icons and how to make new?

I create new project with activity and nav bar.
But, icons at this navigation bar are in XML!
How can i create a new icon and add it instead old icons?

A:

Android has defined its own vector format called VectorDrawable; It works much like SVG, but uses a smaller portion of drawing commands. Although VDs are also using XML as their format, they end up getting compiled into a binary serialization format for distribution in the APK, reducing their overall size. So the savings here is pretty simple, using a VectorDrawable to generate ever resolution of PNGs you need, rather than storing the PNGs directly, can save you a lot of space.
Below URL shows you how to import new images as a vector into your app. https://developer.android.com/studio/write/vector-asset-studio.html
Adding the steps would be a lot here, Hence I have posted the link

