This is where food is provided, usually early in the day, but no break is given and the lunch time is not deducted from paid hours. This is typically used when the catered lunch is scheduled for more than six hours after the call time. People are provided the meal, usually a breakfast, and eat it while they're waiting around. The six hour count begins after the NDM has been served. Usually the NDM is catered, but not always.
Many shows also cater hot breakfasts eaten before the work day starts.
Such things as bacon, eggs, potatoes, sausage, toast, breakfast sandwiches, breakfast burritos, hot and cold cereal, coffee, milk, juice, fruit, bagels, donuts etc. Once again, non union extras may or may not get the best breakfasts. Some will allow non union extras cereal, bagels and the like, but not bacon, eggs etc. The difference here was that non union extras were offered the full breakfast menu if they would pay a couple of dollars. To me that was the ultimate of chintziness.