SP bar/combine button in eq

What purple sp bar shows? I guess its's % needed to achive points for skills on 99lvl, but in what scale?



I have 95 lvl: 34% on exp bar and 65% on sp bar, so it's mean i would get 1 point when i reach 100% on sp bar and its equal to achieve lvl from 95 34% to 96?



Second question: what combine button below in eq is for?