Five data structures every CS student should actually understand

Memorising definitions never helped me. Using data structures in real projects did. Here are five that come up again and again.

Arrays are the default and often enough. Linked lists matter when you insert and remove a lot and do not need random access. Stacks and queues are simple but show up everywhere, from undo history to task scheduling.

Hash maps are the workhorse: when you need fast lookups by a key, reach for one first. And trees quietly power things like file systems and search, so understanding how they keep data ordered pays off.

The trick is not to learn them in isolation. Each time I built a feature in AuraJobs or Nexa, I asked which structure fit the access pattern, and the theory finally clicked.

Written by Khushi Bansal, a final-year Computer Science student at Chitkara University and the founder of Elegant Threads & Beads.