How are the shining and smooth ons made which looks ?

how are the ons which we see in some websites, are shining and so smooth made. the ons look like they are water or shining. can anyone answer plz its not simple html coding? is it css? if yes then wheres the option in dreamweaver to make it. please tell the exact location, i would be so thankfull.have been trying so hard.thank u ...