Question

what is eye droper tool

Answer 1

An eyedropper is a tool found in many image editing programs that let you click on a point in the image to identify and select its color. The picture shows an example of how an eyedropper may appear in a software program.

Answer 2

The Eyedropper tool (the icon in the Toolbar) is used to sample a color from an image to use this color further. It's practical as it facilitates color selection, for example, an appropriate color for the skin or the sky.