The Item Level allows you to set up the Item as a Parent or Child, which in turn allows you to bundle products together. For example, if you want a product to automatically appear on a quote, you can set it as a Child and bundle it with a Parent. The Item Name of the Child Item will be displayed on Quote Create under the Parent Item, and will inherit the quantity of the Parent(s)
Interested in Item Bundling? Check out our Item Bundling Knowledge Base article here.