How do I find out who owns a Internet domain name and its ip address?

How do I find out who owns a Internet domain name and its ip address?

The WHOIS system is used by domains and ip address on the Internet. It is used by system administrators to obtain contact information for IP address assignments or domain name administrators. Use whois command as follows:
$ whois domain-name
$ whois -h whois.example.com domain.com
$ whois google.com
Sample outputs:

Registrant:
        Dns Admin
        Google Inc.
        Please contact contact-admin@google.com 1600 Amphitheatre Parkway
         Mountain View CA 94043
        US
        dns-admin@google.com +1.6502530000 Fax: +1.6506188571

    Domain Name: google.com

        Registrar Name: Markmonitor.com
        Registrar Whois: whois.markmonitor.com
        Registrar Homepage: http://www.markmonitor.com

    Administrative Contact:
        DNS Admin
        Google Inc.
        1600 Amphitheatre Parkway
         Mountain View CA 94043
        US
        dns-admin@google.com +1.6506234000 Fax: +1.6506188571
    Technical Contact, Zone Contact:
        DNS Admin
        Google Inc.
        2400 E. Bayshore Pkwy
         Mountain View CA 94043
        US
        dns-admin@google.com +1.6503300100 Fax: +1.6506181499

    Created on..............: 1997-09-15.
    Expires on..............: 2011-09-13.
    Record last updated on..: 2010-03-30.

Find out IP address and its owner:
$ host -t a google.com
Sample outputs:
google.com has address 209.85.231.104
Now, get ip address information:
$ whois 209.85.231.104
Sample outputs:

NetRange:       209.85.128.0 – 209.85.255.255
 CIDR:           209.85.128.0/17
 OriginAS:
 NetName:        GOOGLE
 NetHandle:      NET-209-85-128-0-1
 Parent:         NET-209-0-0-0-0
 NetType:        Direct Allocation
 NameServer:     NS2.GOOGLE.COM
 NameServer:     NS3.GOOGLE.COM
 NameServer:     NS4.GOOGLE.COM
 NameServer:     NS1.GOOGLE.COM
 RegDate:        2006-01-13
 Updated:        2006-06-01
Ref:            http://whois.arin.net/rest/net/NET-209-85-128-0-1
OrgName: Google Inc.
OrgId: GOGL
Address: 1600 Amphitheatre Parkway
City: Mountain View
StateProv: CA
PostalCode: 94043
Country: US
RegDate: 2000-03-30
Updated: 2009-08-07
Ref: http://whois.arin.net/rest/org/GOGL
OrgTechHandle: ZG39-ARIN
OrgTechName: Google Inc
OrgTechPhone: +1-650-253-0000
OrgTechEmail: arin-contact@google.com
OrgTechRef: http://whois.arin.net/rest/poc/ZG39-ARIN
#
# ARIN WHOIS data and services are subject to the Terms of Use
# available at: https://www.arin.net/whois_tou.html