A Donation Type describes what kind of goods a food item in a donation is. The Types are Surplus, Purchased and Food Appeal. Surplus is the default and is selected automatically.
Not every organisation sees all of the options. If this functionality has been enabled for your organisation, you may see additional Donation Type options when posting a donation. Non-food items are chosen by selecting the Non-food category, not a Donation Type.
To find out how to choose a Type, see Choosing a Donation Type.