What Are Data Structures?
Why structure matters, abstract data types, and how interviews use them.
What you will learn
- Define data structure vs algorithm
- Name common ADTs
- Connect to real code (lists, maps)
A data structure is how you organize data in memory so operations are fast enough for your problem. Picking the wrong one is how a feature that should be instant becomes a timeout.
Common structures
Arrays, linked lists, stacks, queues, trees, hash tables, and graphs — each optimizes different operations (lookup, insert, order, relationships).
Try it yourself
For a chat app's "recent messages" feature, would you prioritize fast append or fast lookup by ID?