A mantra is a word or phrase that is repeated as a form of meditation and concentration. It is a sound, syllable, word, or group of words that is considered capable of "creating transformation." Mantras can be in any language, but are often in Sanskrit, a sacred language of Hinduism and Buddhism. They are used as a tool for spiritual development and to invoke the blessings of deities, spiritual teachers, or specific qualities such as compassion or wisdom.

In Hinduism and Buddhism, mantras are typically used in conjunction with other practices such as yoga, meditation, and puja (worship). They can be recited silently or out loud, and they can be repeated a specific number of times or as many times as desired.

Mantras can be used for a variety of purposes such as purifying the mind, gaining spiritual insight, and achieving a sense of inner peace. They are also believed to have a powerful vibrational energy that can affect the mind and body in positive ways.

Mantras can be divided into three categories:

1. Vedic Mantras: These are the oldest mantras and are found in the Vedas, the ancient Hindu scriptures. They are used for ritual and spiritual purposes.
2. Tantric Mantras: These mantras are used in tantra, a form of spiritual practice that seeks to elevate the individual to a higher level of consciousness.
3. Buddhist Mantras: These are used in Buddhism and are often associated with specific deities or concepts such as compassion or wisdom.

It's important to note that reciting a mantra without understanding its meaning or without proper guidance from a qualified teacher, may not yield the desired results.