Mantras are sacred sounds, words, or phrases used in meditation and prayer in Hinduism. The most powerful mantra is 'Om' or 'Aum', considered the primordial sound of the universe. Mantra meditation involves repetitive chanting or mental repetition of these sacred sounds. This practice helps calm the mind, focus concentration, and connect with the divine. Scientific studies have shown that mantra meditation can reduce stress, lower blood pressure, and improve overall well-being. Popular mantras include the Gayatri Mantra, Mahamrityunjaya Mantra, and various names of deities.