Japa meditation (prayer)
Japa is personal, quiet prayer. Each person repeats the Hare Krishna mantra under their breath on a strand of 108 beads; one full round is 108 repetitions, and devotees usually chant sixteen rounds a day.
From the outside it looks like an hour and a half of near-silence in which everyone is absorbed in their own practice: some walk slowly around the hall, others sit by the wall. In essence it is an hour and a half of deep inward prayer addressed to God.
A guest is welcome simply to be there — or to take a strand of beads and try. Asking how it is done is perfectly normal here.
The same maha-mantra as in kirtan, but differently: kirtan is prayer together — sankirtana — while japa is individual prayer. It is spoken softly, under one’s breath, sometimes in a whisper, yet still aloud. One round of beads is 108 repetitions:
O Lord, O internal energy of the Lord, please engage me in Your devotional service. — translation by Srila Prabhupada