No problem. It’s easier to understand when you can see it in action.
Let’s say you have two lists of different lengths. Combining those lists (or any function taking multiple inputs) will act differently depending on how it manages those lists.
Shortest
The items in each list get combined until the shortest list runs out of indices to match.
Longest
The items in each list get combined until the shortest list runs out of indices to match. Then the last item in the short list gets repeated with the rest of the indices of the longest list.
Cross Product
Each item in the first list will be combine with each item in the second list, regardless of list length.
The confusing part is that sometimes nodes have to be run on Longest lacing to make the list structure work, even if the lists have the “same” number of items (just a different structure). It takes a little bit of experience to figure it out but it’s well worth it. Be sure to also check out running nodes on specific levels of a list. It’s like lacing but with much more control.