The ip nat inside source command identifies what IP addresses will be translated.
In this configuration example the ip nat inside source command configures a STATIC translation between the inside local ip address 10.1.1.1 to the outside global ip address 172.46.2.2. - See more at: http://www.certificationkits.com/cisco-certification/Cisco-CCNA-Network-Address-Translation-NAT-Part-I.html#sthash.Z59p80tL.dpuf