What do the 'listing' and 'let search engines find your blog' settings do?

What do the 'listing' and 'let search engines find your blog' settings do?

love ....

"  love is like a river ..or may be a deep blue sea ...
   love flows on forever... always and endlessly ...
   love is something special ...something you can't ..touch ur see ..
   love is amazing ...this thing i feel for you and you for me ...
   i'm not afraid of death ..i'm not afraid of dying ...

  i'm not afraid of heartbreak ..and i'm not afraid ...some of love story ..live forever...~