sdlc means that software development life cycle.It contais 
various phases for developing a software.The phases are 
analysis,desin,coding,testing and maitences.In each phase 
software will develop step by step.
stlc means that software testing life cycle model.It 
contains various kinds of steps for testing that is test 
plan,test stratigies,usecase,testcase,execution of 
testcase,bugreport,log a bug, verified .This kind of all 
steps used for testing.

HI

SDLC & STLC can be mapped thro V-Model







sun_ramprasad@yahoo.com

STLC is a part of SDLC

Yes SDLC can be maped to STLC with the help of V model.
I have tried to show it
1. Requirement Specifications ---------->  Acceptance Test  
                          Acceptance TP      Cases

2. Functional design -------------------> System Test Cases
                         System TP

3. Detailed design ------------------->Integrated Test Cases
                       Integrated TP
 
4. Program Specifications--------------->Unit Test Cases
                            Unit TP

TP refers to Test Plan and not Time Pass :)

So in each of the phases of SDLC , we start planning and 
writing Test Cases accordingly,this is how u map SDLC with 
STLC.

Hope my answer was fruitful to you

we can map SDLC with STLC thru V-Map
The mapping is as follows:

     SDLC              --  STLC
1)Requirements gathering --- BRS/SRS Document preparation
2)Requirement analysis    --- Test Strategy preparation
3)Software design        ----  Test  design (test plan/test
scenarios and test cases preparation)
4)Functional coding ------System testing
5)Build release ---- UAT/Maintainable testing

There is no separate life cycle called as STLC. Rather, it
is just a phase(Testing phase) in SDLC. 

And V-model is an SDLC where both the testing as well as
development are done in parallel.