SMOKE TEST :
                         Smoke testing is considerd as 
built level test.Each time the test team receives a new 
build(new version of program),an initial test is performed 
to determine that the most crucial functions of the program 
works and the build is stable enough and can be considered 
for further testing.

SANITY TEST :
                          Sanity testing is considered as 
release level testing.When software is ready to be shiped 
to client and we want to finally cheek if everything is 
fine and working as per requirement.It's a sub set of 
Regressing testing -a group of test cases are executed to  
cheek it is indeed working according to specification
(requirement).

  I hope this will do.But somebody may not agry with me as 
this defination will vary company to company... but i think 
this is the basic defination...

Smoke testing - A process of testing weather the BUILT is
ready for further testing or not

this is tester part.

Sanity testing - A process of testing weather the CODE is
ready for further testing or not

this is Developer part after coded developer will do

Smoke testing is useful for checking for the main 
funcnality of the application.it is  also initial type of 
testing. in these chech the futures of the application>
sanity testing also initial type of testing it is also 
called as tester accptance testing.to check the build is 
stable or not.
smoke tetsing and sanity testing conceptually they are same 
but perceputally they are different.

smoke testing is negitive point of view.sanity testing is 
positive point of view.

hello sara,

    u reverse the total definition of smoke testing and 
sanity testing ok.

Smoke testing - A process of testing weather the CODE is
ready to submint for testing or not

this is Developer part after coded developer will do

Sanity testing - A process of testing weather the BUILT is
ready for further testing or not
in this we people check for stebility of the build

this is tester part.