LaserJet in the context of HP Inc.

The HP LaserJet 5 is a group of monochrome laser printers produced in the mid-1990s as part of the LaserJet series by Hewlett-Packard (HP). It is the successor to the HP LaserJet 4 series of printers. After the LaserJet 5 series, however, HP introduced a new naming convention for its LaserJet line. While the LaserJet 5L and 5P were replaced with the LaserJet 6L and 6P, there was never a LaserJet 6; the successor to the LaserJet 5/5M/5N/5se line was the LaserJet 4000 series, and the successor to the LaserJet 5si/5siMX/5siNX was the LaserJet 8000 series. In addition, the LaserJet 4V/4MV was not succeeded by a LaserJet 5 series printer, as its successor was the LaserJet 5000 series.

In computing, an emulator is hardware or software that enables one computer system (called the host) to behave like another computer system (called the guest). An emulator typically enables the host system to run software or use peripheral devices designed for the guest system.Emulation refers to the ability of a computer program in an electronic device to emulate (or imitate) another program or device.

Many printers, for example, are designed to emulate HP LaserJet printers because a significant amount of software is written specifically for HP models. If a non-HP printer emulates an HP printer, any software designed for an actual HP printer will also function on the non-HP device, producing equivalent print results. Since at least the 1990s, many video game enthusiasts and hobbyists have used emulators to play classic arcade games from the 1980s using the games' original 1980s machine code and data, which is interpreted by a current-era system, and to emulate old video game consoles (see video game console emulator).

The HP LaserJet 4 (abbreviated sometimes to LJ4 or HP4) is a group of monochrome laser printers produced in the early to mid-1990s as part of the LaserJet series by Hewlett-Packard (HP). The 4 series has various models, including the standard LaserJet 4 for business use, the 4L for personal use and the 4P for small businesses. Additional models included the 4Si model, created as a heavy-duty business printer, and the 4V model, a B-size printer for desktop publishing and graphic artists. There are also PostScript variants of these machines with the '4M' designation, where M stands for, but is not limited to, usage with an Apple Macintosh. Hewlett-Packard also released an upgraded version of the LaserJet 4/4M known as the 4 Plus ('4+')/4M Plus ('4M+').

The LaserJet 4, especially the 4/4M/4+/4M+ models, have become known for their durability, mainly due to their reliable construction, as well as the printers built-in PCL (and optional PostScript) printer language support which is still used in computers to this day. Hewlett-Packard dominated the laser printing sector during this time in part due to their reliability, relatively affordable pricing, and the spread of LaserJet 4 models from personal use up to heavy business use.