List

ArrayList's resizable-array model, complexity, capacity growth, iteration, and concurrency characteristics.

Java LinkedList as a doubly linked List/Deque, with operation costs and cache-locality trade-offs.

Safe Java List/array conversion and the mutability semantics of Arrays.asList and modern collection factories.

Choosing among ArrayList, LinkedList, CopyOnWriteArrayList, and synchronized wrappers by access pattern.

The synchronized List wrapper, compound operations, iteration requirements, and alternatives.

Legacy synchronized Vector behavior and why ArrayList or specialized concurrent collections are usually preferred.

What ConcurrentModificationException means, structural modification tracking, and why fail-fast behavior is not a thread-safety guarantee.