Each disc is a node, and each wire is a pointer. A pointer is nothing more than the address of another node, drawn as a wire from the knob on top of one disc to the knob of the next. The last node points to null, drawn as an earth symbol.

Paper tags are fields the structure keeps, like HEAD and TAIL. Cobalt tags are variables in the code on the right, like CUR. Watch the cobalt wires: they are the pointers the code has followed, and the chips under the caption count them. Walking to a node costs one hop per node; an array jumps straight to any index.

Memory view moves every node to its real address. The array stays in one block; the list’s nodes are scattered, and only the wires keep them in order. For the queue it unbends the ring into the plain array it really is.