Any WordPress instance include specific files located within root install directory. You may think this is not a big deal as any site contain such file. The problem is they use a format which makes your WordPress easy traceable:
As default a WordPress installation use a wp-content directory which store themes, plugins, media files, cache data etc. This option allow a way to change this slug to something else on front side html.
As default a WordPress installation contain a wp-include folder which store files and resources used on themes and plugin. This section allow a way to change this slug from any links on front side html.