Distributed Computing Systems consist of multiple computers which together form & communicate through a computer network.

A program is divided(distributed) into many individual jobs, each of which is then solved by the computers in the network. One job, per computer.

This is in contrast to parallel systems, where the job is divided but solved by the same computer.

Hence, in case of parallel systems, we have the same memory but different processes, while in case of distributed systems, there are different processes on different memory units.