Which of the Resource Records translates host names to IP addresses?

Which of the Resource Records provides a translation from IP address to name?

Which of the Resource Records defines zones, which roughly correspond to domains?

Which field in the SOA record specifies the length of time that remote name servers should cache records from this zone?

How are symbolic names to specific revisions calleds

Which of the tools can help user to set the name of the host manually?

Which protocol finds Ethernet address of the host, using its IP address?

Which keyword in ipfw rules discards the packet and sends an ICMP host unreachable message to the sender, then stops processing the rules?