Most common type of 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.
Home and Professional Printers
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.
About printing companies
Paints, inks, paper, toners, foils and other consumables - these are things that can not be missing from printing plants. They are ordered wholesale and also consumed in bulk. For each order, the production costs are optimized, and the appropriate technique and type of printing is selected.
Graphic designers, DTP operators and printers deal with this. They are responsible for the quality of the printout and as soon as something is wrong they are the first to be targeted by the dissatisfied boss. Their work is quite hard and I have to admit that you have to really have a fuss to do it. Work after hours, maximum focus and responsibility - definitely not work for everyone.