Trees are one of those data structures that feel simple at first… and then show up everywhere once you start building real systems or doing interviews. File systems. Org charts. DOM trees. Segment trees. Tries. ASTs. You name it. If arrays are about contiguous memory, trees are about structure.
DSA
Trees
January 28, 2026•4 min read•Premium
What Is a Tree?
A tree is a hierarchical data structure that organizes data in a parent → child relationship.