The I Ching book consists of 64 hexagrams. A hexagram is a figure composed of six stacked horizontal lines (爻 yáo), where each line is either Yang (an unbroken, or solid line), or Yin (broken, an open line with a gap in the center). The hexagram lines are traditionally counted from the bottom up, so the lowest line is considered line 1 while the top line is line 6. Hexagrams are formed by combining the original eight trigrams in different combinations. Each hexagram is accompanied with a description, often cryptic, akin to parables. Each line in every hexagram is also given a similar description.