What are the differences between bike chain wax and lube, and which one is more effective for maintaining a bike chain?

Bike chain wax and lube serve the same purpose of lubricating a bike chain, but they have different compositions. Wax is a solid substance that hardens on the chain, providing a protective coating, while lube is a liquid that penetrates the chain's links. Wax tends to last longer and repel dirt better, making it more effective for maintaining a bike chain in the long run.