Emulator means someone who copies the words or behavior of another Synonyms. In computer sciences hardware, software or a combination of the two that enables a computer to act like another computer and run applications written for that computer is called emulator. In the past, it was often a hardware add-on that actually contained an instruction execution module for the emulated computer. Today, “emulator” more often refers to software, which provides a translation layer from the emulated computer to the computer it is running in. understand printer emulation, remember that a printer receives commands from the computer. These commands are in a specific printing language. Many manufacturers have developed printing languages but some of them have become industry standards. To meet the industry requirement manufacturers try to make their printers compatible with these de facto standards. PCL and Postscript are most popular languages and have become a standard, other manufacturers equip their printer according to the specifications of these languages. For example, while PCL was developed by Hewlett–Packard, it was widely copied by other manufacturers who offer emulations of HP printer. By the emulation of a HP printer another printer is able to understand PCL. If you are using an emulated printer, you may find “Laser Jet IIp compatible” or “PCL5 compatible” etc on it.
Adobe does not sell printers but it sells Postscript license to the manufacturers. Before Postscript Level 2, the license fees charged by Adobe were high, so some manufacturers tried to emulate the PostScript language. But nowadays license fees has been reduced and manufacturers prefer to use Postscript instead of emulated languages.