Using the power off button abruptly powers off the Virtual Machine, with no consideration for work in progress. This can damage the file system. If a Virtual Machine is writing to disk when it receives a Power Off command, data corruption may occur.

Shutting down the guest ensures that the operating system recognizes the signal and shuts down gracefully. This protects the file system.

The Progress Kemp VMware Tools add-on package allows you to shut down or restart the guest, as opposed to abruptly powering off or restarting.