Meditation means Dhyana, it was practised since ancient times. Dhyana is found in Upanishads of Hindu philosophy.
Meditation is the integral part of Hinduism, Jainism and Bhuddhism.
Although there is 9 techniques of Meditation, the way of practising is different in different traditions.
Out of 6 types of Yoga, Raja Yoga involves meditation.
Meditation works on mind, in which focus on particular object or thought is involved. So the person is able to channelise unnecessary thoughts which is actually disturbing, distracting.
In Raja yoga breathing exercises in involved during asanas (sitting postures), one can also do mantra chanting during performing asanas.
Meditation is a mind relaxing technology, improves focus, concentration, relieves tensions, clear unnecessary thoughts, cures anxiety issues, improves sharpness of mind, decisive quality, stable emotions etc.
Basically it is a brain exercise, which works on mental plane, improves mental health (neurological, psychological).