What is the difference between ceramic substrate and ceramic substrate

It's not the same!

Ceramic substrate is a sheet material which forms a supporting base for the membrane circuit elements and the outer fitting elements.

Ceramic substrate refers to copper foil bonded directly to the surface of ceramic substrate at high temperature (Single or double sided) on a special craft plate. The ULTRA-THIN COMPOSITE SUBSTRATE MADE OF SILITONG CERAMIC substrate has excellent electrical insulation performance, high thermal conductivity, excellent soft brazing and high adhesion strength, and can be etched out of various graphics like PCB board, with great current carrying capacity. Therefore, ceramic substrate has become the basic material of high power electronic circuit structure technology and interconnect technology.

Simply put, there are no wires on the substrate, and metal wires have been etched into the substrate.