i will reply here so that it helps others also if someone needs such help or understanding ...
tapes are used on parts like SSD drives, rams, any other points on motherboard or components on which you can not attach a heat sink using bolts/retention mechanism ... one can also use it instead of thermal pastes but i dont know how much is the difference (linus tech did such test in past dont remember the verdict)
so parts which produce heat and you want to improve their cooling by attaching a dedicated heatsink ... or you want to develop a contact of such device like ram n ssd with metallic body of the laptop or any such other part of a computer ...
it will only work if your laptop has metallic body and ssd ram or any other chip can be in direct contact with it ...
like Macbook Pro or Dell XPS series
it will not work for every other laptop ...
check how he used this tape in this thread
[CPU + GPU Temperatures + Benchmarks] - XPS 15 [9560] Kaby Lake | NotebookReview