Skip to main content

Basic Data Structures Every Beginner Should Learn

🧠 Basic Data Structures Every Beginner Should Learn

A Simple Guide + Best Free Resources to Get Started

When I started learning programming, one advice every senior gave me was:
“Learn data structures early. It’ll change the way you think.”

They were right.
Understanding data structures isn’t just about interviews — it’s about writing cleaner, faster, and smarter code. Even as a beginner, learning the basics can massively improve your problem-solving skills.

In this guide, I’ll walk you through the fundamental data structures you should learn first, explained in a simple way. I’ve also shared the best free resources where you can learn each one properly.



Let’s get started 👇

🌱 What Are Data Structures?

A data structure is simply a way to organize and store data so you can use it efficiently.

Think of them like containers:

  • Some are great for fast searching

  • Some are best for inserting and deleting

  • Some maintain order

  • Some don’t

As a beginner, mastering even the basics will help you understand how real-world programs work.

📦 1. Arrays

What They Are

Arrays are fixed-size collections of elements stored in a continuous memory block.

Example

[10, 20, 30, 40]

Why They Matter

  • Fast access using index

  • Simple and beginner-friendly

  • Foundation for all other structures

When to Use

  • When size is known

  • When you need fast lookups

Free Resources

  • GeeksForGeeks: Arrays Basics (Free)

  • Khan Academy: Intro to Arrays

  • YouTube: “Arrays Explained Simply” by Kunal Kushwaha

🔗 2. Linked Lists

What They Are

A linked list stores data in nodes, where each node points to the next.

Why They Matter

  • Great for learning dynamic memory

  • Easy insertions and deletions

  • Forms the base for more complex structures like stacks/queues

When to Use

  • When the size of data changes frequently

  • When multiple insertions/deletions are needed

Free Resources

  • Visualgo: Linked List Visualizer

  • Jenny’s Lectures (YouTube): Linked List playlist

  • FreeCodeCamp: Linked List article

🥞 3. Stack

What It Is

A stack works on LIFO (Last In First Out), like a stack of plates.

Why They Matter

  • Used in recursion, undo operations, expression evaluation

  • Helps understand how memory stack works

When to Use

  • Backtracking problems

  • Reversing data

  • Expression validation

Free Resources

  • GeeksForGeeks: Stack Basics

  • Visualgo: Stack Visualizer

  • CodeWithHarry: Data Structure basics

🚶‍♂️🚶‍♀️ 4. Queue

What It Is

A queue works on FIFO (First In First Out).
Think of people standing in line.

Why They Matter

  • Used in CPU scheduling

  • Used in BFS (breadth-first search) algorithms

  • Used in messaging systems

When to Use

  • Processing tasks in order

  • Multi-threading

  • Buffered data transfer

Free Resources

  • Programiz: Queues for Beginners

  • Visualgo: Queue animations

  • YouTube: “Queue Data Structure Explained”

🧵 5. Strings

What They Are

Strings are sequences of characters.
They behave like arrays but have special operations.

Why They Matter

  • Used everywhere: UI, forms, files, APIs

  • Foundation for text processing

When to Use

  • Anytime you work with text

  • Searching, matching, formatting text

  • Interview warm-up problems

Free Resources

  • GeeksForGeeks: String tutorials

  • LeetCode Easy String Problems

  • Harvard CS50 – Strings lecture (Free)

📚 6. Hash Maps (Dictionaries)

What They Are

A hash map stores data in key–value pairs and allows fast searching.

Example

{"name": "Rahul", "age": 25}

Why They Matter

  • Used in almost every application

  • Fastest lookups (O(1) average)

  • Essential for coding interviews

When to Use

  • Counting frequency

  • Caching

  • Searching in huge datasets

Free Resources

  • Harvard CS50 – Hash Tables

  • FreeCodeCamp – Hash Tables article

  • Visualgo – Hashing animations

🌳 7. Trees

What They Are

A tree is a hierarchical structure with parent-child relationships.

Common Types

  • Binary Trees

  • Binary Search Trees (BST)

  • AVL / Red-Black Trees (advanced)

Why They Matter

  • Used in databases, file systems, compilers

  • Basis for search algorithms

When to Use

  • Searching or inserting data in sorted manner

  • Representing hierarchical structures

Free Resources

  • Visualgo: Tree Visualizer

  • Jenny’s Lectures: Tree Basics

  • GeeksForGeeks: Binary Trees for Beginners

🕸 8. Graphs

What They Are

Graphs represent relationships between entities.

Why They Matter

  • Used in maps, networks, social media, recommendation systems

  • Backbone of shortest path algorithms

When to Use

  • Networking

  • Routes, paths

  • Connections and dependencies

Free Resources

  • CS50 Graphs Lecture

  • WilliamFiset Graphs Playlist

  • Visualgo: Graph animations

🧩 9. Heaps

What They Are

Heaps represent a special priority-based tree structure.

Why They Matter

  • Used in priority queues

  • Used in Dijkstra algorithms

  • Used in scheduling tasks

When to Use

  • Selecting top/lowest elements quickly

  • Processing priority tasks

Free Resources

  • Visualgo: Heap animations

  • GeeksForGeeks: Heaps for beginners

  • Abdul Bari (YouTube): Heap videos

📘 10. Tries (Bonus for Curious Beginners)

What They Are

Tries are special trees used for fast searching of strings.

Why They Matter

  • Used in autocomplete

  • Spell check

  • Dictionary apps

Free Resources

  • GeeksForGeeks: Trie Basics

  • YouTube: “Trie Explained Easy”

  • Visualgo: Trie animations

🎁 Best Free Courses to Learn Data Structures (Complete)

Here are full free courses covering everything a beginner needs:

1. Harvard CS50

A complete introduction to CS, algorithms, and DSA.
(Free on YouTube + edX)

2. FreeCodeCamp Data Structures & Algorithms

Beginner-friendly, self-paced, free.

3. GeeksForGeeks DSA Self-Paced Free Track

Great written explanations.

4. Kunal Kushwaha DSA Playlist

Perfect for beginners (Java-focused but concepts are language-agnostic).

5. MIT OpenCourseWare - Introduction to Algorithms

More advanced, but free and legendary.

🚀 Final Thoughts

If you're a beginner, don't rush.
Data structures take time — but once you understand them, your coding skills will transform.

Start slow, practice small problems, and visualize everything.
With consistent effort, you’ll be ready for real-world projects and even coding interviews.

Comments

Post a Comment

Popular posts from this blog

Top 30 Must-Do DSA Problems for SDE Interviews

Top 30 Must-Do DSA Problems for SDE Interviews Here’s a curated list of 30 essential DSA problems that cover arrays, strings, linked lists, trees, stacks, queues, hashing, and searching/sorting. Solving these will prepare you for 60–70% of coding rounds for fresher and early SDE roles. Arrays Two Sum Best Time to Buy and Sell Stock Contains Duplicate Reverse Array (DIY) Rotate Array Maximum Subarray Strings Valid Palindrome Valid Anagram Longest Substring Without Repeating Characters Reverse Words in a String Linked List Reverse Linked List Linked List Cycle Merge Two Sorted Lists Middle of the Linked List Trees Maximum Depth of Binary Tree Binary Tree Level Order Traversal Validate Binary Search Tree Sorting & Searching Quick Sort (DIY Implementation) Merge Sort (DIY Implementation) Binary Search Stacks & Queues Implement Queue using Stacks Valid Parentheses Hashing & Misc M...
Post a Comment
Read more

Machine Coding Round Preparation Guide

  Machine Coding Round Preparation Guide The Fastest Path to High-Paying Software Engineering Jobs Without Heavy DSA Most candidates think that cracking top tech companies requires mastering very advanced DSA, dynamic programming, graph theory, and hundreds of LeetCode problems. But that is not true for many high-paying companies. A lot of top product companies now prefer Machine Coding Rounds (MCR) instead of traditional DSA rounds. These companies are more interested in • real-world coding ability • clean code • working features • modular design • testing skills • day-to-day development knowledge If you find DSA difficult or boring but enjoy building real applications, this interview format is perfect for you. Let’s explore everything. What is a Machine Coding Round? A machine coding round is a hands-on coding assignment where you need to • Build a mini application • Implement core features • Apply OOP , design patterns , and modular design • Handle edge case...
Post a Comment
Read more

Ultimate Learning Path for Aspiring Software Engineers

🚀 Ultimate Learning Path for Aspiring Software Engineers Breaking into software engineering can feel overwhelming — especially when you’re just starting out. But with the right plan and structured resources, you can go from absolute beginner to job-ready developer faster than you think. Here’s a simple, practical roadmap I highly recommend 👇 🧩 Step 1: Start with Easy Coding Questions If you’re an absolute beginner , don’t rush into complex data structures yet. Begin with easy coding problems — the goal is to build confidence and learn to convert your thoughts into code . 👉 Focus on: Practicing syntax and logic flow Understanding problem statements Writing clean, working code on your own This stage will strengthen your fundamentals and make your thinking-to-code conversion faster. 💡 Step 2: Master the Basics with Blind 75 Once you’re comfortable with basic coding, move to the legendary Blind 75 list — a carefully curated set of questions covering all cor...
Post a Comment
Read more