Japa is an Indian Sanskrit word literally meaning “muttering” or “whispering,” but is typically used in the religious or spiritual sense of muttering or repeating prayers, spells, or Mantras.
However, some Indian religious or spiritual lineages don’t consider the Japa practice an actual repetition or chanting of a word or phrase, but rather the contemplation and meditation on the meaning of a Mantra.
In any case, Japa can also refer to verbally or mentally repeating passages of the Veda (the ancient sacred scriptures of India) or the names of deities, or even silently counting the beads of a rosary (called a Japamala in Indian religions). When doing Japa is a regular spiritual or religious activity in one’s life it’s rather called Japa Yoga.
Hence, Japa Yoga is the repetitive reciting of Mantras, spiritual chants, or the name of a God or Goddess. It’s in fact a form of Bhakti Yoga, that is, the Yoga of Devotion i.e. a practice of worship. The Japa practice is found in religions that originated in India, such as Hinduism, Buddhism, Jainism, and Sikhism. It can be performed alone or in a group setting.
The idea behind persistently doing Japa as part of one’s Sadhana practice is that it leads to liberation of worldly ignorance and bondage, peace and bliss, and finally to Self-Realization i.e. Spiritual Enlightenment.
Typically, Japa is performed sitting in an Asana (Yoga pose) or meditation posture, and the Mantra or Divine Name of the Deity is spoken loud enough to hear (Vaikhari Japa), whispered (Upamshu Japa), or only spoken silently in the mind (Manasika Japa).
It’s thought that the way one performs a Japa has various degrees of effectiveness, where Vaikhari Japa is the least powerful and Manasika Japa the most powerful form.
Doing Japa may be accompanied with other practices, such as burning incense or counting beads that glide through the hands. A special form of Japa is Likhita Japa. In this Japa Yoga practice one repeatedly writes the Mantra (for instance, in a notebook) while reciting it. It’s thought to be even more effective than only reciting a Mantra.