Parallel and serial ports are interfaces for connecting peripherals to the virtual machine. The virtual serial port can connect to a physical serial port or to a file on the host computer. You can also use it to establish a direct connection between two virtual machines or a connection between a virtual machine and an application on the host computer. You can add parallel and serial ports and change the parallel and serial port configuration. Hardware version 11 and later versions allow you to configure virtual machines in such a way that serial and parallel ports are absent from the virtual chipset altogether.
Starting with vSphere 7.0, you cannot add, remove, and configure parallel ports. For information, see https://kb.vmware.com/s/article/78978.