What is the differences between COB and SMD

What is the differences between COB and SMD:
COB package is Chip Onboard, which is to stick bare Chip On the interconnect substrate with conductive or non-conductive adhesive and then carry out lead bonding to realize its electrical connection.
SMD means: surface mount device, it is one of the SMT components.
COB can reduce the cost of LED lighting by 19% to 32% compared with traditional SMD light sources, which can greatly reduce the