[Print Job]
When a user sends a print request to a printer, that request is often referred to as a "print job".
[Print Spooler]
Because Unix print services must accommodate multiple users and multiple printers at the same time, a mechanism to control access to the system's printers is required. The Unix print spooler is a software mechanism for buffering or storing data on its way to a specific printer destination.
[Printer Queues]
Because Unix is a multi-user and multi-computer environment, print requests are submitted to a printer "queue". A print job waits in a printer queue just like you wait in a line to buy a ticket at a movie theater, or stand in a line at the grocery store.
In the queue your files, and the files of other users, are stored in the order they are submitted until they can be printed to the appropriate printing device. (If there are no other files in the printer queue, your print request will not have to wait for other jobs.)
Printer queue names on SCO Unix 3.2.4.2 systems can have up to 14 characters.
[Interface Programs]
Interface programs are used to initialize printers and (possibly) format the file output to take advantage of unique printer capabilities. Different printers will use different interface programs.
Interface programs are usually written as Unix shell scripts. The standard SCO Unix interface programs are located in /usr/spool/lp/model.
[Device]
The term device usually refers to a Unix device file. For instance, the device name for the first parallel port on a system is "/dev/lp0", and the device name for the first serial port on the system is "/dev/tty1a".
