Data Structures, Explained Like You're Five: Linked Lists
A linked list is a treasure hunt. Each clue holds a prize and tells you where the next clue is hidden. You can't skip ahead to clue five — you have to follow the trail one clue at a time. That trail of "this points to the next one" is the whole idea.
The whole idea in one sentence
Every item (a "node") holds its value plus an arrow pointing to the next node, and a "head" pointer remembers where the trail starts.
Watch it happen
Hit Play. We build the list by adding nodes, then search for a value (notice we have to walk from the head — no jumping), add a node to the front instantly, and delete one from the middle by re-pointing a single arrow.
Why interviewers like it
Linked lists are the classic trade-off against arrays. Adding or removing from the front is instant — no shifting everything over — but finding the 5th item means walking five arrows instead of jumping straight there. Knowing when that trade is worth it (and being comfy re-pointing arrows without losing the rest of the list) is exactly what pointer-heavy interview questions test.
Insert/delete at a known spot: O(1), just re-point an arrow. Find an item: O(n), you have to walk. Arrays are the mirror image — instant lookup, slow insert.