What is the difference between hash table and B-tree data structures?

A hash table and a B-tree are different data structures for organizing and searching data.

• Hash table uses a hash function to compute an index where the value is stored. Search, insert, and delete operations are usually performed in amortized O(1). However, a hash table does not support ordered traversal of elements.

• B-tree is a balanced tree with multiple keys in a node, optimized for disk storage systems. Search, insert, and delete operations are performed in O(log n). B-trees support ordered traversal of elements, which is important for databases and file systems.

Example: if you need to quickly search for elements by key without sorting — use a hash table. If ordered access and range queries are important — use a B-tree.