A microkernel architecture is called a plugin architecture because of the way capabilities and functionality are added to a minimal core OS. They're an efficient way to achieve application customization and can offer software lifecycle benefits

https://www.techtarget.com/searchapparchitecture/tip/What-is-a-microkernel-architecture-and-is-it-right-for-you#:~:text=A%20microkernel%20architecture%20is%20called,can%20offer%20software%20lifecycle%20benefits.