Appletalk zones are configured by Mac Servers. They are used to differentiate different sections of a network, similarly to workgroups on Windows. However, unlike Windows, you cannot specify an AppleTalk Zone, only join an existing one. If you enable AppleTalk on your computer, it will find all the AppleTalk systems in your subnet, and you can communicate, just under the default settings.
It is common for school districts that have interconnected the schools to designate a different zone for each school. In most cases it is not a requirement to have an AppleTalk zone to use AppleTalk.
TEG