Each hexagram is accompanied with a description, often cryptic, akin to parables.
Each line in every hexagram is also given a similar description.
The Chinese word for a hexagram is 卦 "guà", although that also means trigram.
Classic and modern I Ching commentaries mention a number of different hexagram types: The most commonly known sequence is the King Wen sequence.
A totally different sequence was found in the Mawangdui Silk Texts.