Most properties in the maintenance system feed down, meaning that they are copied from the work order or tasks into the assets that are part of the job.
Job Number for instance is copied from the work order into each of the individual assets that are part of the job.
However, a few properties - most importantly, the status of the job - feed upwards.
These feed from the individual items back to the task or work order.
So if you have a job that works with one asset, setting the job status on that asset to 'complete' will then mark the entire job as complete.
If you have multiple assets involved in the job, the overall work order will take the lowest value. So if three assets are marked as 'complete' (with value '100') and one is marked as 'blocked' (value 0), the order as a whole will appear as blocked.
Clicking on the job status in most pages will show you how the status is calculated in a report such as the one below.