Symlink etc

I’m really new to Ruby so have patientce. I got this instruction from my
web host:
“Put application catalog outside public_html and then create a symlink
from myapp/public catalog to public_html/myapp so it will be accessible

So I create a catalog parallel to pubic_html? But how to create a
symlink. Is this a good instruction:

Is myapp/public the suggested shortcut?