Digital Printing or Direct To Garment is a newer process that involves your artwork being processed by a computer, and then printed directly onto the surface of your garment. DTG (direct to garment) is not a transfer - the ink is directly adhered to the fabric of your shirt. The fact that the design is processed and printed digitally allows for low quantity of garments to be printed with full color, photographic designs, since there are no screens or physical setup.
DTG is best used for items that require large amounts of detail and/or print colors, customers that require water based ink, and for orders of a smaller quantity. The fact that the digital printer does not use screens allows for a print with much more detail than traditional screen printing. As the ink is applied thinner, digital printing is best used on lighter colored shirts to allow the design to shine through.