Do hair straighteners soften hair or only straighten it?

-For examply does it only straighten the hair.My hair is alot like this https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhs5gEebVYxVfrxGOWSywVT_k5RnjNB-RaB5jppolBLC8DyB5ho2DWklN8XJmAi08PrV92H4Zl40rWRImVT92oGiUc3gIS38NegDcb_Z15XboN_FRoAFnkfnMDDKQWJSxJ2IqOTVjRuOtY/s1600/asian-afro.jpg



I wanted to know will a hair straightener only straighten but still keeping it hard or will the heat soften the hair as well as straighten it.If yes how can I get it shiny like the second link.



Thank you very much.