Dynamic arrays and linked lists can both represent ordered sequences, but their costs come from different physical layouts.

Dynamic arrays

A dynamic array stores elements contiguously. Indexed access is constant-time, traversal has strong spatial locality, and append can be amortized constant-time. Inserting in the middle usually moves later elements.

Linked lists

A linked list stores separate nodes connected by references. If the insertion position is already known, adding or removing a neighboring node can require only a few pointer updates. Reaching an arbitrary position still requires traversal.

Big-O is not enough

A theoretically cheap linked-list operation can lose in practice when finding the node dominates the work or scattered nodes cause cache misses. Conversely, linked structure is valuable when stable node identity or constant-time local splicing is actually needed.

Choose the data structure from the operations and memory-access pattern of the workload, not from one isolated complexity entry.