This screen is used to enter the usual item types/mediums you carry in the Gallery See LOCATION.. Item types can cover a very broad range of items, from gifts to furniture to originals.
When you edit an Item Type, you can also assign a Category to it. So the Silver Print ItemType might be part of the Photography category.
Suppose you have an Item Type like OIL ON CANVAS. Suppose this type is the 8th one in your list of item types.
Now, you create a new item that you want to be OIL ON CANVAS. You add or edit the item and select OIL ON CANVAS (the 8th type in the list) from the item type drop down list. In the database, the system doesn't actually store the words OIL ON CANVAS. It simply remembers that the item you are adding is an item type number 8.
In computer terms, this is called "normalizing" the data. There are a couple of good reasons for doing this.
Lets say you have 1000 pieces that are oil on canvas. You can imagine that putting the words OIL ON CANVAS in the database 1000 times takes a lot more memory than storing simply the number 8 1000 times.
Also, suppose you misspelled the item type when you originally entered it as OIL ON CANVS and then added the 1000 pieces - all with the wrong spelling. By making the data work the way we do, you can simply change the spelling (using the item type screen from the lists menu) to correct the spelling. As soon as you do this, all 1000 pieces that had item type 8 would instantly change to the correct spelling.