SVG is often the way to create an image, that format is scalable and easy to maintain. But still many applications need an icon `*.ico`. So it is necessary to convert the SVG to an icon. There are many online tools doing that, but I was not able to found any which can handle multiple resolutions in one ico-file. A icon normally can handle multiple resolutions in one single file. A icon is normally a square.
The resolutions are 16x16, 32x32, 48x48, 64x64, 128x128, 256x256, …