Understanding Malas
The Buddhist name for prayer beads is mala. In Sanskrit, it means garland. Buddhist history shows they have been in use from at least 100,000 BC to the present.
Their purpose is used to count the number of times the mantra is breaths of meditation, prostrations, or repetition of the Buddha's name.
Beads are similar to other forms of prayer beads that are in various world religions. Malas are often referred to as the Buddha's Rosary.
From about 100,000 BC to the present day, tools have been used to count the number of times the mantra is meditated, or counting prostrations or the repetition of the Buddha's name. Similar forms of prayer are used by many other world religions. Buddhist prayer beads are often referred to as "The Buddhist Rosary."
In Chinese, the literal meaning of malas is "Buddha's pearls." In Japan, however, there seems to be a Romanization, meaning countable Roman letters. As best as I could understand. Nenjyu or Juzo seems to mentally count or repeat the mantra or name of the deity.
In Sanskrit, mala means the convention of the Buddhist tradition. It counts 108, signifying the mortal desires of mankind. It is said that Sakyamuni Buddha instructed one of his followers to make such beads. Some sects would also decorate them with tassels or talismans.
The Japanese bead Ojuzu (counting beads) Onenju, also known as thought beads with strands at both ends, are similar to those used in Mainland Asia.
There are an assortment of beads, shapes, and uses in Japan depending on what sect or school you belong to. Each also uses them differently. Nichiren Buddhists have longer beads with strands on both ends and are similar to those used in mainland Asia. This formation represents a human body with hands, feet, and head. This is the formation or configuration I use.
Over time, various sects would either change or retain their 108 count depending on their various schools as well. You can find out more about the 108 count. In Nichiren Buddhism, 108 equals 108 earthly desires. Nichiren Buddhist beads have additional beads with further means and configurations.
There are probably a million different diagrams and explanations. SGI-USA has the most definitive diagram and explanation, along with other interesting bits of information regarding the spread of Buddhism and its significance.