NOTE
Array
Contiguous indexed storage, constant-time random access, resizing, insertion/deletion costs, and cache locality.
This is a historical learning note and may contain outdated or incomplete understanding.
An array stores elements in indexed contiguous/logically contiguous positions, enabling constant-time random access by index.
Insertion/removal in the middle generally requires shifting elements. Dynamic arrays add spare capacity and occasionally allocate/copy to grow, giving amortized constant-time append.
Arrays provide excellent locality and low per-element overhead, which often matters as much as asymptotic complexity in real programs.