With offset printing the image (your artwork) is transferred to metal plates and then from the plates to a rubber blanket.
Then the inked blankets transfer the image onto paper.
The process is called offset because the ink is first transferred from plate to blanket rather than going directly on to the paper.

Digital presses use powdered toner instead of traditional inks and with the digital printing process,
Your artwork goes straight from your pdf to print.
Early digital presses couldn’t compete with quality produced.
Huge technological advances in the last couple of decades have resulted in digital print.
Your artwork goes straight from your pdf to print.
Huge technological advances in the last couple of decades have resulted in digital print.

Screen printing as we know it has been around since the early 20th century and is used for printing fabrics, wood, glass, signage etc.
The image is transferred to a fine mesh and areas to be left blank are covered with a substrate.
The printing process involves pushing ink through the openings in the mesh onto the end material.

High volume refers to large print runs with quantities of tens or hundreds of thousands.
Price per copy printed goes down when you get into these quantities.
(It’s worth pointing out that we’ve never heard of any printer for returns policy
so if you print 10,000 leaflets and realise you can only distribute 1000,
you’ll need a bigger recycling bin.)