It is a program to observe the internal structure of the earth.
The crust - mantle - outer core - inner core.
You can zoom in and out.
You can also move inside the district.
In the lower right corner, it is indicated by an arrow somewhere inside the earth.

When moving, you need to know how fast you are traveling
When zoomed in and out, we have shown how much the actual scale is.

Moving down from the crust
You can see that the Earth is huge.
The crust is thin, too.

You can also compare the size of the earth's inner structure with the size of a person by introducing a human model. The thickness of the crust is similar to the thickness of the hair.


Source: https://sciencelove.com/892 [Kim, Jeong Sik]