A
distributed operating system is a software over a collection of independent,
networked,
communicating, and physically separate computational nodes. Each individual node holds a specific software subset of the global aggregate operating system. Each subset is a composite of two distinct service provisioners. The first is a ubiquitous minimal
kernel, or
microkernel, that directly controls that node’s hardware. Second is a higher-level collection of
system management components that coordinate the node's individual and collaborative activities. These components abstract microkernel functions and support user applications.