Explain why the TreeSet collection contains the word 'Tree' in its name?

In the TreeSet collection, the word "Tree" reflects the underlying data structure it is based on — a balanced tree (usually a red-black tree). This tree provides ordered storage of elements and efficient search, insertion, and deletion in logarithmic time.

Unlike HashSet, which uses a hash table and does not guarantee the order of elements, TreeSet stores elements in sorted order thanks to the tree. Therefore, the name emphasizes that the implementation is based on a tree, ensuring order and performance.