I have finally understood the resolution of twin paradox. If you choose the earths frame of reference you will see that the travelling twin's time runs slowly on his both outward and inward journey. So he ends up younger. In the frame of reference that runs with the travelling twin in the outward journey; the travelling twins time is the proper time and the earths time runs slowly but after the turn-around the travelling twin's time start to run much more slowly than the earths time so in the end the travelling twin ends up younger. Same result will be arrived if viewed from the frame of reference that moves with the travelling twins inward journey. Now my question is because the travelling twin isn't in inertial frame of reference I can't use SR to see what things will look like from his perspective? My attempt answer: I can however split up what he sees. During the outward trip he observes the other twins clock to run slowly. Also during his return trip also he sees other twins clock run slowly. But since he is to find the other twin much older on the meeting, the resolution should be that --> At the turn-around he should find the other twin instantly grow much older so that even if he continuously grow younger he would anyway finally end-up older. If all my reasonings are correct then please let me know.