named.conf and zone files

[latcarf]

I have been reading a document about securing Bind and it disusses the use of views, internal and external. I noted the zones in named.conf are the same with the exception of the file.

Can anyone tell me what the difference is between an internal zone file and a external zone file for the same domain?

I have Googled for a couple days with no luck on examples. The closest guess I have is that the external zone file does not contain A records for network computers.

One other question... I am building two servers on two different machines. One will be primary DNS and mail with www and FTP. The other will be secondary DNS and mail. Is a reverse zone not needed in the secondary for the domain/nameserver?