Delivery checkout ID is always the highest level. You can build your entire structure from one ID. If you have more than one webshop, operate on different markets with different carriers, and support several countries, languages and currencies, it is a good idea to consider more than one delivery checkout.
A delivery option is either a service, or a container for services, for example, agent delivery services. Sublevel is optional and is used to group services. A general recommendation is not to display too many overlapping delivery options.
Addons, carrier-specific or custom addons, can be added for services on delivery option level or sublevel. For most delivery options, services, prices and addons it is possible to enter appliance conditions.
You can also use advanced conditions to modify certain text fields dynamically.
Before creating your delivery checkout it is recommended to explore delivery conditions further.