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How do the crown and root of a tooth differ in location and function?

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A labeled cross section illustration of an adult human molar shows the tooth's crown and root, with layers including enamel, dentin, and pulp, as well as gum, cementum, blood vessels, periodontal ligament, lateral canals, and nerve. — tooth Cross section of an adult human molar.

The crown and the root of a tooth are distinct in both their physical location and their primary biological roles:

Location: The crown is the portion of the tooth that is visible above the gum. In contrast, the root is the unseen portion of the tooth that extends below the gumline and is embedded within the jawbone.12
Function: The crown serves as the functional part of the tooth used for activities such as mastication, cutting, and grinding food. The root serves to support and fasten the tooth securely within the jawbone, attaching to the alveolar processes via the periodontal ligament.12

While the crown is typically covered by a hard layer of enamel, the root is covered by cementum, which provides a medium for the attachment of the fibers that hold the tooth in place.2