The most culturally significant meaning of 章 is seal (印章, yìnzhāng).
In Western culture, a signature is the ultimate mark of personal agreement and identity on a document. In China, the seal holds that power, and often, even more.
The Seal vs. The Signature: A personal or company seal, often carved from stone, wood, or jade, is impressed onto documents using red ink paste. Historically and legally, this red stamp (盖章, gàizhāng) is often considered more official and legally binding than a handwritten signature. A contract might be signed, but without the company's official red seal, it could be deemed invalid.
A Symbol of Identity and Art: Unlike a utilitarian signature, a Chinese seal is an object of art and status. The calligraphy of the characters carved into the seal is a respected art form. For centuries, artists, scholars, and emperors have used unique seals to mark their work and correspondence, making the seal a deep part of China's artistic and bureaucratic heritage. This connects to the value of tradition, authority, and tangible proof in Chinese culture.