Laser printing in Wikipedia
Laser printing is an electrostatic digital printing process. It produces high-quality text and graphics (and moderate-quality photographs) by repeatedly passing a laser beam back and forth over a negatively charged cylinder called a "drum" to define a differentially charged image.1 The drum then selectively collects electrically charged powdered ink (toner), and transfers the image to paper, which is then heated in order to permanently fuse the text, imagery, or both. As with digital photocopiers, laser printers employ a xerographic printing process. However, laser printing differs from analog photocopiers in that the image is produced by the direct scanning of the medium across the printer's photoreceptor. This enables laser printing to copy images more quickly than most photocopiers.
Why do we need standards?
Standards in every industry and business are important. Imagine that we buy a monitor and its input does not match our video card, even though it has the same type. That's why certain standards apply.
In polygraphy and graphics, such standards also exist - appropriate definitions of CMYK colors - key for the appropriate color reproduction. Specified in advance formats for printing leaflets and business cards, so that they are comfortable and as uniform as possible. Without standards, even leaflets could be completely unreadable and even repulsive.
Who today does not have a printer at home. Their prices are becoming more affordable and operating costs lower. Multifunction devices offer increasingly larger scanning resolutions, less margin, larger formats, etc.
But still, such home printers are far behind the professional equipment used in professional printers. Not to mention the much larger range of techniques used, which have nothing to do with those we know from home printers. Printed roll, solvent, water, anhydrous - long to exchange. The quality of such printouts is higher, which entails the obvious higher costs of printing itself.