The  word  "Mantra"  has  its  roots in  the  Sanskrit  word "man", meaning  "to  think".   The  literal  sense  of   the  word  means "instrument of thought". In the context of the Vedas, it refers to hymns  or  the  portion  of   texts called Rig Veda, Yajur Veda or Sama  Veda  which  when  spoken  are  believed  to benefit   the person chanting them. Vedic  mantras are  the invocations to the deities  and God  for  protection against  evil forces and negative environment.  These  also  help the  chanter in performing his or her duties to the fullest.

Many experts  agree that if any mantra is  recited quietly or in the mind, it is very effective.  In Agni Puran,  their effectiveness is said to depend on  the  correct  recitation of  the  hymn and the focus of mind while  reciting them.  Although mantras  originated in the Vedic tradition of  India,   they later became an indispensable part of other religions as well including Buddhism, Sikhism,  and  Jainism.  The use of mantras is now  widespread throughout different cultures and various spiritual movements.

The deeper understanding of a mantra may help a person in knowing about different traditions as the words of it also depend on the context in which it is written or  even sounded.  In  some cases,  multiple  layers of  symbolism are associated with every different sound, some of which are specific to particular
line of thought.