Which better monolithic or microkernel-based kernel operating systems ?

Monolithic kernel is considered as a single large processe running in a single address space. It will be treated as a single static binary file and hence a faster entity.

while in Microkernels, the kernel is divided into separate processes, known as servers. Some of the servers run in kernel space and some run in user-space. All servers are separate to each other and run in different address spaces.The communication between them is done by message passing and hence is a slower entity. 

microlithic kernals apperared in1980s. Monolithis is older than this.Monolithic kernal is a single large processes running entirely in a single address space.It is a single static binary file. In Microkernels, the kernel is broken down into separate processes, known as servers. Some of the servers run in kernel space and some run in user-space. All servers are kept separate and run in different address spaces.The communication in microkernels is done via message passing. The servers communicate through IPC (Interprocess Communication). Servers invoke "services" from each other by sending messages. The separation has advantage that if one server fails other server can still work efficiently.

I agree with all answers