functional testing is a testing process where we test the 
functionality/behaviour of each functional component of the 
application...i.e.minimize button,transfer button,links etc.
i.e we check what is each component doing in that 
application...

regression testing is the testing the behaviour of the 
application of the unchanged areas when there is a change 
in the build.i.e we chk whether the changed requirement has 
altered the behaviour of the unchanged areas.

the impacted area may be the whole of the application or 
some part of the application...

Hi,
  
   In Functionality testing we are going to check the 
functionality is working as expected to the client 
specified requirement.

   In regression testing means after getting confirmation 
the bug is fixed we are going to check the fixation is 
going to create any problems in the application or not...


Regards,
Satya.K

Functionality testing is to test the functional behaviour 
of each and every component in the application. its tested 
against both positive and negative aspects.
Regression testing is the re-execution of same old test 
cases written for earier releases.

A major part of black box testing is functional tetsing. 
testing team more concentrate on functional testing.
for ex any gui application the basic functionality will be 
like these.
if u click on minimized button it will be minimized .
if u click on submit button it will go to the next page. 

regresion testing means in any application new functiality 
can be added so the application has to be tested to see 
whether the added functialityes are affected by the 
exsiting functiality or not.