Test Driver - A program or test tool used to execute 
software against a test case suite. 

Stubs - A skeletal or special-purpose implementation of a 
software module, used to develop or test a component that 
calls or is otherwise dependent on it. After [IEEE].

Test driver is a s/w component or module used to test the 
submodule in the absence of main module.

Test stub is a dummy module to receive calls from main 
module.It is used to test the main module in the absence of 
sub module

STUB:while intergrating all the modules in top to bottm 
approach whenever any mandatory module is missing that 
module is replaced by a temperoary program which is called 
as stub.
DRIVER:while integrating all the modules in bottom to top 
approach whenever any mandatory module is missing that 
module is replaced by a temperoary program which is called 
as driver.

Both are temporary programs while we executing the program 
in under constuction. stub is calling program and driver is 
a called program.

Integration testing has diffirent testing techniques.
Top Down,Bottom up,hybrid.
If any submodule is absent in topdown approach then tester 
will put a dummy module known as Stub.
If main module is in bottom up testing then we can put a 
dummy module at thre place of main module this module known 
as Drivers.