Look at these common different parts. You can see them everywhere in your life. Coca cola cap, shampoo cap, soy sauce cap and so on.
How are they made? They are made from plastic injection molding. Or paint the color after injection molded. They can be in any shape with texture on the surface. Check the place you are living around, you can see lots of and lots of plastic injection molding parts. Technical manufacturing help people to improve life.