The C-Shell family has a clear separation between environment variables and shell variables. The Bourne shell family is not so clear, because a newly created variable is, by default, a shell variable....

The C-Shell family has a clear separation between environment variables and shell variables. The Bourne shell family is not so clear, because a newly created variable is, by default, a shell variable. If it is exported, it becomes both a local and an environment variable. What are the advantages and disadvantages of each system? Which system do you think is better, and why? Why do you think the Bourne shell family has such a confusing way of dealing with variables?