virtual hosting config

[Guest_imported]

hi

I'am trying to create virtual domains (I have xyz.com and I'am trying to
create a.xyz.com and b.xyz.com etc. and respective sites for those two
domains) on Apache web server under Linux 6.2.

I shall be grateful if somebody can help me out with the process.

I have an elementary query here, if I do create a.xyz.com how does a
browser resolve the DNS name to point to my site (xyz.com)

THanks in advance and anticipation

Regards
Sachin