Printers feature various specifications, so navigating the spec sheet intelligently requires familiarity with what each specification entails according to the printing technology involved or for the type of usage planned for the printer.
o Resolution: For laser printers, 300 dpi is adequate if all you need is to print black-and-white text, but choose at least 1200 dpi for photorealistic grayscale or color printing. For inkjets, choose one featuring 1200-dpi or higher resolution with a droplet size of 4 picoliters or smaller for sharp, clean output. With photo printers, resolution varies according to technology: Output at 300 dpi by photo printers using dye-sublimation technology is comparable to photo printers using inkjet technology outputting at 1200 dpi or higher.
o Speed: Speed ratings vary greatly, and the print speeds cited by manufacturers usually refer to printing in draft mode or at the lowest resolution. For laser printers, a more accurate way of measuring actual print speed is to time just how long it takes from the minute you hit "Print" -- to the time that it takes the printer to warm up, spool the job into the print queue, and for the printed output to finally come out. For inkjets, print speed is not one of its stronger suits; so don't be overly concerned with this spec.
o Memory: Extra memory will come in handy for laser printers to enable them to handle large graphics and documents more easily. Check the maximum upgradeable memory allowed for your printer, if it features a hard drive with similarly upgradeable memory, and if the printer can use generic memory or needs the manufacturer's brand. In the case of inkjets, memory is built-in and not upgradeable, but this is not an issue inasmuch as processing occurs on the side of the computer -- so there's no need for large amounts of installed RAM to begin with on inkjets.
Source: PrinterCentral