A label is the most common name that an item would be known by. Labels are added to the text fields at the top of an item page to the "Label" column. Click "edit", type in the label, and click "save". A description is a short phrase designed to disambiguate the page in question from other pages with the same or similar labels. Descriptions are added in the same way as labels, to the "Description" column. See Help:Label and Help:Description for more on using labels and descriptions.