What are the differences between Shimano 600 and Shimano 105 components?

Shimano 600 and Shimano 105 components are both high-quality bicycle parts, but there are some key differences between them. Shimano 600 is an older series known for its durability and smooth shifting, while Shimano 105 is a newer series with updated technology and lighter weight. Shimano 105 components are generally considered to be more advanced and offer better performance than Shimano 600.