Every world system contains:

1 Mount Sumeru;

1 set of the Four Great Continents, namely:

• • • • Jambudvipa to the south,
      • Pūravavideha to the east,
      • Aparagodānīya to the west, and
      • Uttarakuru to the north;

1 sun, and 1 moon.

One thousand of such world systems is called one small-thousand world system. A thousand small-thousand world systems is called one middle-thousand world system. A thousand middle-thousand world systems is called one great-thousand world system. Because the word “thousand” occurs three times, the great-thousand world system is referred to as the three thousand great-thousand world system. This gigantic world system contains limitless Buddhalands, and in spite of its name, the number of worlds it contains may vary, because phenomena are flexible, not fixed. One should not become too attached to an exact number.