A ghost process has exited but still occupies an entry in the process table. Its work is done, but it lingers, waiting for its parent to notice.

Operating systems are full of processes like this — things running quietly in the background that nobody thinks about until something breaks. Services that have been running for years without anyone knowing why. Configuration files that outlived the systems they were written for.

Most background work is invisible because it’s working. We only notice it when it fails.

The traces are always there. You just have to know where to look.