Do subdomains have their own options, features, and email accounts? Can subdomains use freeCGI or CGI?

Subdomains(subwebs) on a subdirectory have their own IP address, and they are aliased to the directory using the IP. Subdomains/subwebs may have their own email accounts. Some of the bundled CGI utilities will work with these, but some do not work or don't work as expected. The subdirectory aliases are intended for minimal hosting needs when a full web account is not needed thus sparing the added expense.