STSADM Export / Import

Uses STSADM commands to generate a file (export) which can then be transferred to the target for import. One of the simplest ways of moving content from one place to another, although unlikely to be suitable as a continuous deployment mechanism. 

Examples:

Export:-

stsadm.exe -o export -url http://localhost -filename C:\Export.bak -includeusersecurity -versions 4 -overwrite

Here,

http://localhost - Your actual web site address

C:\Export.bak - Your actual path where do you want export the web site

Import:-

stsadm.exe -o import -url http://localhost/newsite -filename C:\Export.bak -includeusersecurity

Here,

 http://localhost/sites/newsite - Your actual web site address

 C:\Export.bak - Your actual path where did you export the web site

Reference

http://www.sharepointnutsandbolts.com/2007/10/stsadm-export-content-deployment.html