Glossary

The glossary includes definitions of terms used in the Advanced Printing Software documentation.

Access Control List (ACL)

A list of entities (such as users, operators, administrators, and servers) used to determine whether a certain entity has authorization to perform some operation or function.

administrator

A class of user that is enforced by security. An administrator sets policy and can create, modify, and delete persistent print system objects such as printers and servers. See also operator and user.

attribute

Characteristics of an object relating to its identity, physical makeup, or status. Every print system object contains a collection of attributes that provide information about that object. See also object.

authentication

The process of identifying and verifying the user making a request by checking and validating the user's credentials.

authorization

The process whereby an access policy determines whether an authenticated entity can perform a particular operation.

logical printer

A named object of class printer that is used to group one or more physical printer objects for load balancing and for specifying alternative default attributes to those specified by the physical printer object.

LPD Client

The client that communicates by LPD protocol.

LPD protocol

Line printer daemon protocol for print systems used by the Berkeley versions of the UNIX operating system. It is described in RFC 1179.

name service

A set of capabilities provided throughout a network environment by servers that allow client applications access to names of user-defined and system-defined objects.

notification

Result and error reporting by a server to the client that had requested its services. Generally, the mechanisms needed to implement notification are provided by the system infrastructure. In most system environments, electronic mail can be used as a crude means for notification.

object

An abstraction used to represent various entities, such as printers and queues. Each print system object contains a collection of attributes. See also attributes.

operator

A class of user, defined by POSIX and X/OPEN, enforced by security. An operator can perform day-to-day operations, such as pausing and resuming jobs and printers and disabling and enabling printers. See also administrator, user.

output device

A printer. A physical device or hardware that is capable of rendering images or documents. A marking engine.

physical device

An actual output device with specific characteristics and capabilities. See also physical printer.

physical printer

A software representation of a physical device. Physical printer objects reside in supervisor processes and their databases. See also physical device.

POSIX

The IEEE standards body that is chartered with standardizing portable operating system interfaces. In this document, POSIX refers to the operating system interface standard for printing: POSIX 1387.4-System Administration-Part 4: Printing Interfaces.

queue

A spooler object that partitions logical and physical printers. A given printer can only exist in a single queue, thus queues partition printers into disjoint sets. The default print system spooler configuration is a single queue. Within a queue, a logical printer can be associated with one or more of the physical printers of the queue. The default association is to all of the physical printers.

Additionally, queues impose an ordering on the jobs submitted to the logical printers of the queue. This imposed order is known as selection order. The algorithm for this ordering is configurable (FIFO or shortest job first).

server

A software component that manages printing facilities on behalf of a client or clients on the same computer or over a network. For the print system, the term is generally used to refer to the print server that is either the spooler or the supervisor, but not both. Specifically, the spooler is a print server to the various API, CLI, and GUI clients that access it directly. However, the spooler is also a client of the supervisor for which the supervisor is a print server to the spooler.

spooler

An ISO DPA and POSIX object of class server. A specialization of a server object. A named server that accepts print system operations from print clients and schedules print jobs on appropriate printer supervisors. The typical spooler is multithreaded and is capable of processing multiple print operations concurrently.

supervisor

An ISO DPA and POSIX object of class server. A specialization of a server object. A static process or software to drive a specific printer for the printing of print jobs. A supervisor is entirely responsible for interpreting the job request. This includes interpreting the content of each file and reconciling the instructions provided in the print request parameters with the contents of each file. The supervisor has complete control over the printing of the job, including the loading of fonts, forms, and other electronic resources into the printer, as well as over transferring each file to the printer.

user

A class of user, defined by POSIX and X/OPEN, that is enforced by security. A user (unprivileged) who submits print jobs and gets status. See also administrator, operator.