Japa is the chanting or repetition of a mantra, which is a kind of prayer. Japa is also a meditation on the sound of the mantra. Perhaps the best example of japa is the chanting of the Hare Krishna mantra: hare krishna, hare krishna, krishna krishna, hare hare; hare rama, hare rama, rama rama, hare hare. Another mantra that is commonly recited as japa is the gayatri mantra. Usually some means of counting is employed such as a set of beads like a rosary set. Such beads are called a japa mala and a devotee may follow a vow to recite a mantra a specific number of times a day as part of his or her personal spiritual practice, sadhana. A set of Hindu chanting beads generally contains 108 beads. Such beads may be made of sandalwood, crystal or in the case of Shaivas rudraksha seeds or in the case of Vaishnavas tulasi wood. You may often hear the expression mantra-yoga or japa-yoga to mean that one is using the recitation of mantras as one’s main spiritual practice.