Both Malt extract (Dry Malt Extract Powder) and Malt Syrup (Liquid Malt Extract) are made from Pilsner barley using vacuum drying. However, Syrup has 80% malt while 95% for dry malt powder. Arishtam Prefers DME because it is a more concentrated form and powders have longer shelf life and ease in transportation. There is a separate malt powder that is used in the baking industry. This is a powder of diastatic grains. This cannot be used for wort making as the enzymes have not yet converted starch into maltose needed for your beer.
Liquid Malt Extract and DME can be created from variety of grains. The most popular being Barley, Wheat and Sorghum. The advantage with Sorghum Malt Extract is that it is gluten free.