See the picture here: https://en.wikipedia.org/wiki/Linked_list
That’s a singly linked list (can only go from the front and traverse to following elements)
Each value knows where the next one is. Insertion is just a matter of changing what the next one is, no need to move anything.
You won’t need or even find them useful for what you’re doing, because you probably just need to append at the end, and python’s list does that just fine.
There are other ways of storing data that makes other operations possible (while trading away other properties)
Dicts have fast lookup, insertion, deletion. But they don’t represent order
Lists represent order, you can get things immediately by location, and you can change things quickly at the end. Replacing values is fast anywhere, because everything else stays in the same place. Adding or removing anywhere else means moving which is slow
Linked lists can change at the ends, and can insert anywhere quickly. But finding something that isn’t at the ends requires starting at one of the ends and moving towards your element (so 6 steps to find element number 6)
…and so on, arranging the data in different ways allows for doing different things with them.