Multi-access Network - a network such as ethernet where more than one device can use the physical and link layer of the network, thus requiring a CSMA/CD protocol for shared use.
Multi-tasking - when a CPU is shared and multiplexed by a scheduler in order that multiple threads with state information may execute on a single CPU or may be mapped onto a set of CPUs dynamically. Tasks include state information that goes beyond the minimal requirements of register state, stack, and PC for a thread - e.g. task variables, a task error indicator, name, and many other elements of a VxWorks TCB.
Multi-threaded - when a CPU is shared and multiplexed by a scheduler with the minimal management of execution state for each thread of execution (register state, stack, and PC).