1. Usage: The carriage is a part of the passenger train, which mainly provides passengers with seats, sleeping berths, catering and other services, while the carriage is a space for loading goods or articles on a car or train, which is mainly used for transporting goods.

2. Definition: A carriage is a part of a car and a part of a train. It consists of a car body, a seat, a sleeper and so on. A carriage is an independent concept, which refers to a container or space for loading goods. It can be a part of a car or an independent container.

3. Structure: The carriage has a fixed structure and layout, including seats, sleepers and aisles. The carriage has a simple structure and is a closed space for storing goods, which can be loaded and unloaded as required.