Glossary255GlossaryOSIOpen Systems Interconnection (OSI) is a model developed by the InternationalOrganization for Standardization (ISO) for communications. OSI offers astandard, modular approach to network design that divides the required set ofcomplex functions into manageable, self-contained, functional layers. The layersare, from top to bottom, Application, Presentation, Session, Transport, Network,Data Link and Physical.PABXA private automatic branch exchange (PABX) is an automatic telephoneswitching system within a private enterprise.PCLPrinter Command Language (PCL) is a Page Description Language (PDL)developed by HP as a printer protocol and has become an industry standard.Originally developed for early inkjet printers, PCL has been released in varyinglevels for thermal, dot matrix printer, and laser printers.PDFPortable Document Format (PDF) is a proprietary file format developed byAdobe Systems for representing two dimensional documents in a deviceindependent and resolution independent format.PostScriptPostScript (PS) is a page description language and programming language usedprimarily in the electronic and desktop publishing areas. - that is run in aninterpreter to generate an image.Printer DriverA program used to send commands and transfer data from the computer to theprinter.Print MediaThe media like paper, envelopes, labels, and transparencies which can be usedin a printer, a scanner, a fax or, a copier.PPMPages Per Minute (PPM) is a method of measurement for determining how fasta printer works, meaning the number of pages a printer can produce in oneminute.