Is most of a tree's trunk made of growth rings?

Most of a tree's trunk is not made of growth rings, but these rings are an important part of its structure. Growth rings, formed by annual layers of new wood, represent the tree's growth over time and can be seen when a trunk is cross-sectioned. The trunk itself is primarily composed of various types of wood, including sapwood and heartwood, which provide strength and support. The growth rings help indicate the tree's age and growth conditions but are just a part of the trunk's overall composition.