OFFSET PRINTING PRESS
Offset lithography, often either called just "offset" or "litho" printing, refers to traditional print presses. Paper is streamed through rollers and against a printing "plate," normally four times - once for each of four colored inks used to achieve full-color glossy results. The plate attracts oil-based ink to form your design, and the plate itself is now normally created directly from a computer image of your design .
DIGITAL LASER PRINTING
Digital laser printing is very similar to popular color photocopying—a digital image of your design is digitally transferred to a rotating drum. The drum uses an electrostatic charge to attract toner (colored powder rather than ink) which is then transferred to paper and "fused" by heating to make it stick.
Digital laser printing is a simpler process than using a printing press, and there are no "set up" costs as no costly printing plate is required. Because of this, digital laser printing is more economical for short-run printing jobs up to a few hundred copies, but the results are less glossy and at typically around 600 dots per inch resolution are comparable to high-quality desktop output—slightly lower quality than offset printing.
Digital laser printing is perfect for small-quantity and low cost print runs, it is a particularly quick and easy printing technology.