Om Mani Padme Hum

This Mantra is popularly known as 
" The Jewel in the Lotus "or 
" The Diamond in the Lotus "
( "mani" means Diamond , a precious jewel 
and Padma means Lotus flower which is the
spiritual symbol of consciousness )
The Jewel refers to the Mind or consciousness and
the Lotus refers to the Heart that is the source of Love energy
The meaning of OM MANI PADME HUM is
"Om , salutations to the Jewel of consciousness (the Mind)
which has reached the Heart's lotus. "
A Very Very Important Message Regarding Mantras 
Your outer world is governed by 
your inner world, so Divine Powers 
that are generated inside you , 
now start making all positive events
happen in your life in the outer world.