Imagine a treasure hunt 🗺️:

• You find clue #1 in your mailbox. It says: “Go check under the doormat.”
• Under the doormat is clue #2: “Look in the kitchen drawer.”
• In the kitchen drawer is clue #3: “Treasure is in the garage!”

Each clue holds a value AND tells you where to go next. That’s exactly a Linked List!

A Linked List is a chain of nodes, where each node has:

1. Data — the value (like the clue)
2. Next — the address of the next node (like “go to kitchen”)

flowchart LR
    HEAD["HEAD"] --> N1["Node 1
Data: 10"]
    N1 --> N2["Node 2
Data: 20"]
    N2 --> N3["Node 3
Data: 30"]
    N3 --> N4["Node 4
Data: 40"]
    N4 --> NULL["NULL
(end)"]

    style HEAD fill:#7c3aed,color:#fff
    style N1 fill:#4f46e5,color:#fff
    style N2 fill:#4f46e5,color:#fff
    style N3 fill:#4f46e5,color:#fff
    style N4 fill:#4f46e5,color:#fff
    style NULL fill:#dc2626,color:#fff

HEAD
 │
 ▼
┌─────┬───┐    ┌─────┬───┐    ┌─────┬───┐    ┌─────┬──────┐
│  10 │ ●─┼──▶ │  20 │ ●─┼──▶│  30 │ ●─┼──▶ │  40 │ NULL │
└─────┴───┘    └─────┴───┘    └─────┴───┘    └─────┴──────┘
  Node 1         Node 2         Node 3         Node 4

• HEAD = pointer to the first node (entry point)
• NULL = means “end of list” (no next node)

Think of an array like a row of seats in a movie theater — all glued together. If you want to add a seat in the middle, you have to move everyone.

A linked list is like friends holding hands in a line. To add someone in the middle, two people just let go and grab the new person’s hand. Nobody else moves!

Array — items sit next to each other:

[10][20][30][40]   ← all in one block

Linked List — items can be anywhere in memory, connected by arrows:

[10] ──▶ (somewhere far) [20] ──▶ (another place) [30] ──▶ NULL

• Types of Linked Lists — Singly, Doubly, and Circular
• Time & Space Complexity — Performance analysis
• Core Operations — Insert, delete, traverse, search