If Lightroom is copying the files from the source (copy vs add), then during the import you can configure Lightroom to copy your images to a second location in the "file handling" pane.
It can if you want it to. It can make a Copy of them other than where you specify to place them.
Lightroom is a Image Database, Cataloging, and editing program. It does not Store file inside its own folder structure.
Please do a Google search on how to use Lightroom and specifically the Import dialog window. There is a wealth of information available on using Lightroom, what is does and doesn't do and how it works.