In hashing, collision resolution is carried out by close addressing. Which of…

Hash-table collision resolution splits into two families based on WHERE a colliding key ends up being stored. Open addressing (also called closed hashing) keeps every colliding key inside the hash table's own array, relocating it to another slot within that same array via a probe sequence (linear probing, quadratic probing, double hashing) — no extra memory is created. Close addressing (also called closed addressing, or chaining / open hashing) instead creates a separate auxiliary structure for each slot specifically to hold colliding keys — most commonly a linked list — so a colliding key is stored outside the table's own array, in memory allocated only when a collision happens.

Applying that test to the two named techniques: the technique described as contiguous storage places a colliding key into another position within the hash table's own array — no separate collision-handling memory is created for it, matching the open-addressing pattern. The technique described as linked storage creates a new node in a structure attached to the slot specifically to hold the colliding key, outside the table's own array — matching the close-addressing pattern exactly.

This lines up with how the two terms are traditionally split: close addressing (also called closed addressing) names the array-external, per-slot chaining approach, while open addressing (occasionally also called closed hashing — a separate point of terminology overlap) names the in-place, same-array approach. A technique that keeps every key inside the table's own array — however that array is organised — sits in the open-addressing family rather than close addressing.

So the linked-storage technique (Chains) is the close-addressing technique among the two listed here; the contiguous-storage technique (Buckets) belongs to the open-addressing family instead.