In principle, everything that comes out of the printing house can be included in the category of printing. There are plants specializing in the production of only a specific group of printed materials: eg leaflets, or only large-format printing.
However, this results from a simple thing: for every type of printing you need to have the right machine, and these take up space and cost a lot.
That is why printing plants limit the amount of services provided.
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.
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. .