I've been using Linode for about a year, and am still confused by 'Master' Domain Zone and 'Slave' Domain Zone terminology on their DNS Manager. The term 'Zone' in conjunction with 'Master' AND 'Slave' do not seem to be used anywhere else online except for DNS server names.
I understand a 'DNS zone' can refer to just a single domain.
What I don't understand is, in the CONTEXT of virtual hosts, when would you add a 'Slave Zone' record to the Zone File?
Also, in the case of virtual hosts residing at a single IP, would there be one Zone File, or multiple Zone Files on the associated DNS server?