In the printing process we talk about dot angles, what does it mean? And what are the correct angles?

In this case first of all we designing in art work computer base it's mean pixel or we call it bitmap so after designing we handover to RIP Machine (Raster image Processor) then we geting catoons it's depening on the how much color in there. in the catoon we can see the dot angles. that dots transfer to the paper ture the printing plate. there have dots angles commonly printer using 1. ( C 15% M 75% Y 0% 45%)   2. (C 105% M 75% Y 90% B 15%)