What is a Mantra ?
Mantra - ‘Man’ means mind and ‘tra’ means vehicle or conveyance. In Vedic Meditation, we use specific mantras from our tradition that guide the mind from the gross level of thinking, aka lots of thoughts, to it's least excited state of no thought.
Vedic Meditation mantras have no intended meaning and works on the level of it’s sound characteristics.
Thinking the mantra involves no concentration, no control, no force or anything hypnotic.
Learning the correct mantra that best resonates with you and how to think the mantra effortlessly can only be taught by a qualified teacher of Vedic Meditation.
My teacher Thom Knoles did a podcast explaining the history and mechanics of Vedic Meditation Mantras that I highly recommend listening too. The episode is titled "What are Vedic Meditation Mantras and how do they work".