clarify handling unit

Hello,

I have found some useful postings on handling unit.

But I still like to further clarify or confirm my understanding is correct.

Simply put :

A handling unit is a container truck. Correct?

I also like to confirm the following:

1. these are packaging materials : Carton, Pallet and container.

2. A handling unit can consist of other handling units. But what is an example of this? Could someone give me a clearer example? Is it a Container ship containing many container trucks with containers?

Sincerely

Bass