A microkernel implements all drivers as user-space programs, and implements core features like IPC in the kernel itself. A monolithic kernel, however, implements the drivers as a part of the kernel...
Porcelain is made with kaolin clay. Kaolin is white clay that retains its white color when fired. It is fired at temperatures in excess of 1300 C and is more fully vitrified than stoneware. It is usually covered with a clear glaze, which allows the white body to show.
However, porcelain, pottery, and stoneware may also be referred to as ceramics.. A ceramic item is not necessarily of a lesser quality than a porcelain item. Porcelain is a very specific subcategory of ceramics, or (to put it simply) just one of many types of items created from baked clay.