The Designs module works by have a parent design, and then items assigned to each design.
A design can have multiple files assigned to it. For example, you might have a certain file for T-Shirt and another for Phone Cases whilst using the same artwork.
To design can also have multiple items. An item is an online listing where your design can be found. For example, an item can be a Merch By Amazon T-Shirt or a Hoodie.
To make it easy to group designs, you have the ability to tag them. This way, you can quickly identify all your Christmas designs, Llama designs or both! The search functionality also lets you search by design name, and gives you the option to filter down based on if items are active or not.