What is DSA (Data Structures and Algorithms)?

DSA is the study of how to organise data efficiently and write procedures that solve problems as quickly and with as little memory as possible.

Data structures ways of storing and organising data:

• Array: Numbered list; fast to access by position
• Stack: Last in, first out (like a stack of plates)
• Queue: First in, first out (like a shop queue)
• Tree: Hierarchical structure (like a folder system)
• Hash Table: Value pairs for very fast lookups

Algorithms precise steps to solve problems. Sorting a list, searching for an item, finding the shortest path each has multiple algorithms that differ enormously in speed.

DSA is the foundation of software engineering interviews at Google, Amazon, Microsoft, and others.

DSA separates code that works from code that works efficiently at scale.