Hosting,Domain,DNS Clear Explanation

Domain Name(xyz.com) - is a address which point to you website(index.php)

each domain name as associate to domain zone file

zone file contain all the detail which are required for the browser or any one to come to your address (that is a website)

this zone files have multiple sections, one of the example domain have following sections

xyz.com
DNS zone files
1.A(Host) - Exact IP address which your domain actually located(this A record points to physical IP address where the website for boobal.com has been hosted)
2.AAA(IPV6)
3.CName(Alias) - actually like sub domain
for examble
host             points to
email          email.rajaram.com (if i search email.boobal.com which automatically redirect to email.rajaram.com)
ftp               @
www           @    (the same domain access by www.boobal.com or boobal.com)

4.MX(Mail Exchange) - is where the email for this particular website is configured.
5.TXT(text)
6.SRV(Service)
7.NS(Nameserver) - tell your browser where exactly the website running
host           points to
@              ns73.domaincontrolar.com - these are the godaddy nameserver, whenever browser request comes to boobal.com the control is transferred to this particular name server (ns73) and this server which resolve which ip address your particular website is running.
@              ns74.domaincontrolar.com
and so on  you can refer list of DNS Record here