MATLAB: When using parallel computing, why wait

Parallel Computing Toolbox

In the parallel computing toolbox, there is an option "wait", to suspend the local matlab session until the remote job is completed. This option is commonly used in examples. I have a basic confusion regarding this: does this defies the purpose of running job remotely, or in parallel? what would be the advantages of waiting?

Best Answer

When coding, you often have a sequence of tasks, some of which are serial and some of which are parallelized. The parallelized tasks shouldn't pass their output forward to a serial task until all parallel workers have finished. Otherwise, they may pass forward partially processed data. Hence, you have wait commands to let all parallel workers catch up.
Does that make sense? Maybe I need to see the example you're thinking of.