do multiple sites hosted a machine with a single IP

[samurai]

share a TCP port 80? If a single machine with a single IP address is hosting multiple sites with different server programs, for instance, IIS, apache, tomcat, do these sites share the TCP port 80?
If yes, how can this happen?
Thank you in advance!
do multiple sites hosted on a machine with a single IP share a TCP port 80?

[fire bLade]

yes!
The sites are routed through DNS server.