Understand Data Structures visually

Contiguous indexed sequence

An array is the basic collection for keeping values in order and reading them directly through integer indexes. It is the first structure you reach for when the question is fundamentally about position: what is at slot 0, slot 5, or slot n.

Pointer-linked sequential collection

A linked list is a sequential structure where each element stores not only its value but also a reference to the next element. The collection is held together by connections between nodes rather than by one contiguous block of memory.

Search tree with sorted order

A binary search tree (BST) is a tree that preserves an ordering rule: every key in the left subtree is smaller than the current node, and every key in the right subtree is larger. Its value is not only that it can find a key, but that it stores sorted order inside the structure itself.

Complete tree for priority access

A binary heap is a complete binary tree that preserves a local priority rule between each parent and its children. In a min-heap the smallest key is at the root; in a max-heap the largest key is there. The point is not to keep everything globally sorted, but to make the next highest-priority item cheap to access repeatedly.