Water and waterless - offset printing
Offset printing is the most popular type of printing in today's printing industry. It is true that it has many varieties and uses different techniques and materials (paint, paper). The main division is cold printing, where the paint is fixed by soaking into paper. While the 'hot' offset where the printed paper web passes through the drying tunnel.
The classic offset (water) is associated with the use of water rollers and hydrophilic and hydrophobic surfaces, however, this method is already abandoned due to the difficulty in obtaining a good balance of water and oil paint.
The successor of this method is anhydrous offset printing where silicone molds are used instead of water.
Computer printer in Wikipedia page
In computing, a printer is a peripheral device which makes a persistent human-readable representation of graphics or text on paper. The first computer printer designed was a mechanically driven apparatus by Charles Babbage for his difference engine in the 19th century; however, his mechanical printer design was not built until 2000. The first electronic printer was the EP-101, invented by Japanese company Epson and released in 1968. The first commercial printers generally used mechanisms from electric typewriters and Teletype machines. The demand for higher speed led to the development of new systems specifically for computer use. In the 1980s were daisy wheel systems similar to typewriters, line printers that produced similar output but at much higher speed, and dot matrix systems that could mix text and graphics but produced relatively low-quality output. The plotter was used for those requiring high quality line art like blueprints.
Źródło: https://en.wikipedia.org/wiki/Printer_(computing)
DTP
The DTP operator is a responsible person in printers, publishing houses and wherever materials are printed in large quantities, for the correct preparation of files that will be printed. The task is easy and simple in theory, however, one small error of the DTP operator and the circulation of several thousand copies of newspapers can be thrown away. In this work, many things may go wrong: change of paper for another, new printer with other inks, incorrect conversion of colors. There are also typo errors, bad placement of some element or just a few details. All this can end very badly and bring big losses - so it's work under stress and tension, because if something goes wrong it usually will be just for the DTP operator.