A printer sitting on the network doesn't understand your document. It understands a language, and the driver is the translator that turns your file into instructions the printer can execute. Pick the wrong translator and you get garbage output, missing fonts, or nothing at all.
CompTIA A+ Core 1 (220-1201) covers printers and multifunction devices, and this part of the objective expects you to know the two major page description languages, PCL and PostScript, along with how printer firmware fits into installation, configuration, and troubleshooting. You should be able to tell which driver suits a given office, explain why output looks wrong when the language is mismatched, and describe what a firmware update does and why it can be risky. This guide stays focused on what a technician actually configures and checks in the field.
A printer driver is a translator, and the language it speaks matters
When you print a document, the application hands the file to the operating system, and the operating system hands it to the printer driver. The driver's job is to convert that on-screen content into a stream of instructions the printer can process. That instruction set is written in a page description language, or PDL. The PDL describes what goes on the page: where text sits, what fonts to use, how lines and images are placed, and what colors to lay down.
This matters because a printer only understands the languages it was built to interpret. If you send PostScript data to a printer that expects PCL, the printer may spit out pages of raw code, print partial output, or simply error out. The driver and the printer's language support have to match. In exam terms, a mismatch between the installed driver and the printer's PDL is a classic cause of garbled output, and you should recognize it immediately.
There's a second layer worth understanding. Some languages ask the printer to do most of the work, and others ask the computer to do most of the work. Where that processing happens affects speed, print quality, and how consistent the output looks across different machines. That single distinction explains most of the practical differences between PCL and PostScript, so keep it in mind as you read the next two sections.
PCL is fast, printer-friendly, and built for the office
PCL stands for Printer Command Language, developed by Hewlett-Packard. It's one of the most widely used page description languages in office environments, and you'll find it supported on a huge range of laser and inkjet printers, not just HP models. When a business needs to print invoices, spreadsheets, memos, and everyday documents at speed, PCL is often the driver of choice.
The defining trait of PCL is that it leans on the printer's hardware. The driver sends relatively lightweight instructions, and the printer's own processor renders the final page. Because the printer does much of the rendering work, PCL jobs tend to spool quickly and print fast. The computer isn't tied up building a heavy, fully described page image, so throughput is good for large volumes of routine documents.
That efficiency comes with a trade-off. Because PCL relies on the printer to interpret and render, output can vary slightly from one printer model to another. A page printed on one PCL device may not be pixel-for-pixel identical to the same page on a different device, since each printer's rendering engine handles fonts and graphics its own way. For most office work this variation is invisible and irrelevant. For precise graphic design or professional publishing, it can be a problem.
PCL has gone through several versions, and you may see references to PCL 5 and PCL 6. PCL 5 is the older, well-established version with strong compatibility. PCL 6 (sometimes written PCL 6 Enhanced or PCL XL) is more modern, often producing smaller print files and faster processing. On the job, you'll frequently see both a PCL 5 and a PCL 6 driver offered for the same printer, and you should know that either will generally work, with PCL 6 usually being the better default for newer systems.
For the exam, remember the profile: PCL is fast, hardware-assisted, common in offices, and ideal for general-purpose business printing. Its weakness is that output consistency across different devices isn't guaranteed.
PostScript is the choice when the page must look exactly right
PostScript was created by Adobe, and it's built around a different philosophy. Instead of leaning on the printer to render the page, PostScript describes the page in complete detail before it ever reaches the printer. The result is a precise, device-independent description of exactly how the page should look. Send that same PostScript file to two different PostScript printers, and you should get output that matches very closely, because the page was fully defined up front rather than left to each printer's interpretation.
This makes PostScript the standard in graphic design, publishing, and any workflow where accuracy and consistency are non-negotiable. When a designer needs a proof that matches the final printed product, or when a document contains complex vector graphics, precise color, and scalable fonts that must reproduce faithfully, PostScript is the safe answer. It handles curves, gradients, and detailed imagery with a level of fidelity that general office drivers don't promise.
The cost of that precision is processing overhead. Because PostScript describes the page in full detail, the files are larger and more complex, and interpreting them takes more work. That work happens either in the printer's PostScript interpreter, which requires a more capable and more expensive printer, or on the computer, which uses more system resources. Either way, PostScript jobs can be slower to process than PCL jobs, especially for graphics-heavy documents. For high-volume plain-text office printing, that extra overhead buys you nothing.
You'll also see the acronym PPD, which stands for PostScript Printer Description. A PPD file tells the system about a specific PostScript printer's capabilities, such as its available paper trays, resolution, and features. When you install a PostScript printer, particularly on macOS and Linux systems, the PPD is an important part of getting the printer configured correctly.
For the exam, remember the profile: PostScript is precise, device-independent, and the standard for graphics and publishing work. Its weakness is slower processing and higher cost compared with PCL.
PCL and PostScript side by side
The two languages are easiest to remember when you compare them directly.