1) A smoke test is scripted--either using a written set of 
tests or an automated test

1) A sanity test is usually unscripted.

2) A Smoke test is designed to touch every part of the 
application in a cursory way. It's is shallow and wide.

2) A Sanity test is used to determine a small section of 
the application is still working after a minor change.

3) Smoke testing will be conducted to ensure whether the 
most crucial functions of a program work, but not bothering 
with finer details. (Such as build verification). 

3) Sanity testing is a cursory testing; it is performed 
whenever a cursory testing is sufficient to prove the 
application is functioning according to specifications. 
This level of testing is a subset of regression testing.

In short Sanity testing is done to test testablity of a 
product or an application. Testablity means the application 
or product should be able to be tested. Some examples of 
testability is application should be undersatable, Should 
be able to run, should be stable.In other words sanity is 
done to confirm wheather a product or an application is 
ready for testing or not.

Smoke testing is done to test the overall major 
functionality of an application ofr a product.

Hi,
Smoke testing is performed right after the build is 
delivered to test team. We check whether the build is 
stable by going through all the major pages, 
forms,links,butons etc. If the build is stable we move 
ahaed and perform sanity testing. Sanity testing covers 
entire build with thorough functionality checking. We do 
extensive testing here by executing test cases. 
If smoke testing fails build is revert back to the 
development team.

Regards
JAi

Smoke testing :
-------------

This ensures that the new build is working fine or not..if 
its success then the build will be accepted otherwise it 
would be rejected...In simple we can say sanity testing is 
to ensure the Build.

Sanity Testing :
---------------

This is for starting the Testing process on a 
application..This testing is populary known as environment 
shakedown.It touches the End to End funcitonalities of the 
application to be tested.If it fails the test execution 
cant be performed otherwise we can go ahead with the test 
execution..In simple we can say smoke testing is to give 
the signal to start the test execution on a particular 
application...

(Update me if i'm wrong...)

Regards,
Dinesh.