MANTRA or Mantar is derived from the Sanskrit words consisting of the root man- meaning "mind" and the suffix -tra meaning, "tool", hence a literal translation would be "mind tool". So a Mantra is a tool for the mind. In Sikhism, a mantar is a Shabad from Gurbani to concentrate the mind on God and the message of the Gurus.
Mantras have two components of primary importance - Meaning and Sound. First is the actual meaning of the word or words and the second is the effective sound (vibration). For the mantra to be effective, great emphasis is put on correct pronunciation and the level of concentration of the mind on the meaning of the word or words that are recited.
Due to this emphasis, some care has to be taken regarding the place and surrounding in which the mantras are recited; the way in which these are delivered - ie, a loud; quietly; in a group; with music; without music; etc
The purpose to mantras is to deliver the mind from illusion and material inclinations and to bring concentration and focus to the mind.
Chanting is the process of the continuous repeating a mantra.
See also Mool Mantra