Advanced Keyword-Driven Testing is one of the frameworks 
that are available in QTP. It is a set of files that 
contains all the required functions to execute the test 
case actions like click button, click links, input text in 
text box etc.,

Once all the functions are ready we can use the functions 
names called keywords to execute the test cases. We just 
call the keyword and provide the object logical name that 
is obtained during object spy and the test data in a excel 
sheet.

For example, all the functions are in functions.vbs file 
and the test cases as test.xls.

Then in QTP, call 

ExecuteFile "C:\qtp\functions.vbs"
ExecuteFile "C:\qtp\test.xls"

In xls sheet it will be
Keyword             Object            ObjectValue
Input               txt_firstname     Raj  
Input               txt_lastname      Reddy 
Clickbutton         btn_submit        index


With this framework we can achieve the optimum independency 
of record and playback. The above one is just an example 
and may differ from company to company based on their key 
work framework.