Okay,lets see if i could explain it to you in a right and easy way,the DNA is the plan of the structure to be created,the RNA is the supply of the materials to the structure to be build,they taking the DNA which having a two coiled strands in which the information of the structure to be build were stored,the single DNA has two coiled of strands and their taking it out the other from the other,then their looking it out carefully each elements that has in there,each nucleotides,their looking at it on the part which the weak or unwanted particles must be removed and replace with a new one,after doing that they put it it back to the coil from the origin of the double helix,the strands were they took it,they doing this to make sure that the new cell to be created would be perfect or stronger than the DNA origin,taking out the problems or abnormalities from it...rom the repair of the cell that they have done...