noun
Used for a chapter or major section of a book, thesis, law, report, or similar structured text. Very common in numbering such as 第一章.
この本は全十章から成る。
This book consists of ten chapters.
試験までに第三章を読んでおいてください。
Please read Chapter 3 before the exam.
noun, noun, used as a suffix
Often appears as the 章 element in compounds such as 勲章, 校章, and 社章, referring to an official mark, badge, medal, or emblem.
彼は長年の功績により勲章を受けた。
He received a medal for his many years of service.
制服の胸に校章が付いている。
The school badge is attached to the chest of the uniform.