In Infoplus, Parcel Shipping indicates shipping an order via a parcel carrier, such as UPS, FedEx, DHL, USPS, etc. (Use the standard "Ship Parcel Order" process to ship parcels.)
Non-parcel shipping is shipping via any other method, such as LTL (Less than truck load), TL (a full truck load), Will Call (where recipient comes to warehouse to receive the item), local carrier, etc.