Newbie question -- snmpwalk

[Prakash]

Hello All,                          When  I issue a command like this                snmpwalk -v 1 -c public localhost  SNMPv2-MIB::system.sysName              SNMPv2-MIB::sysName.0 = STRING: hostname                 If I set the sysName value I  in the snmpd.conf file then I get that value.               But if I dont set that value from where does the agent  get this information from     Thanks, Prakash