What is the difference between bending & roll-bending ?

Bending means using flexible wires to bend and know the direction of piping while roll bending means using machines to bend pipes

The  difference between bending and roll bending is,bending has an angle while roll bending has no angle.

difference of bending is a straight bending or sharp one bend jist like a angular bar,compare to roll bending,roll bending is a type of bend with a smooth curve like for example the pipe if we can curve it without using a welding machine to curvre it out,we must use a roller to keep it smoot and clean.and  one more a pressure tank and a water tank we will use a roll bending istead of bending

Roll bending uses rollers.