shumanhum

I am new to the world of 3d printing, and to everything surrounding it especially cura. I made a 3d model of a phonecase and uploaded it to cura, and learned the basics of how to prepare and slice it. when i sliced, the timer said it would take about 15 hours to print, and a lot of materials and i didnt quite understood why the thing that takes most of the time of the print is the ''skin'', and I cant figure out anywhere what thats mean. can someone please explain to me what does skin mean in ''time estimation''? I am using cura 5.3.0 poco x3 phonecase.3mfpoco x3 phonecase.3mf