Explaining GPT to a 5-Year-Old

So, second assignment from Hitesh Choudhary sir and Piyush Garg sir – "Explain GPT to a 5-year-old." Aur mujhe laga, 5 saal ka bacha toh mere chote cousin jaisa hogya, so let’s try to make it simple-simple.

Ek simple kahani

Bacche, socho tum ek kahani sun rahe ho:

"Once upon a time, there was a little puppy..."

Aur main ruk gaya.

Tum turant sochoge — puppy kya karega? khelega? bhaagega? so jayega? Tum guess laga rahe ho based on jo tumne pehle stories me suna hai.

Bas GPT bhi yahi karta hai — next word guess karta hai!

GPT ka full form

GPT ka matlab hai: Generative Pre-trained Transformer

Generative – new cheezein bana sakta hai (stories, poems, code...) hence generative

Pre-trained – already pehle se bahut saara data padh padh ke seekh chuka hai

Transformer – ek type ka brain design (architecture) hota hai jo words ke beech relations samajhta hai. Matlab tumne ek input diya aur usne tumhe ek output.

Lekin wo output hota h next word(ya token) ko predict karna using uska pre-trained data. Jab tak special character(jaise end of string) nhi mil jata tab tak next word predict karta jayega transformer.

Kaise kaam karta hai?

1. Tum GPT ko kuch shuru ka sentence doge

2. Wo apni training ke basis pe next word(ya token) predict karega

3. Phir uske baad ka next word…

4. Aur aise hi poora answer bana dega

   Example:

   Tum: "The sun is" GPT: "shining brightly in the sky."

   Har word bas ek guess hota hai — but smart guess!

Guess karne ka secret – Tokens

GPT directly words me kaam nahi karta, wo tokens use karta hai. Token ka matlab hota hai chhote pieces of text.

Example: "My name is Sanskar"

Kisi model me ye ho sakte hain 18 tokens (har character ek token)

Kisi me ho sakte hain 7 tokens (poore words ko split karke)

GPT tokens pe guess lagata hai, words pe nahi.

Training vs Using

Training phase – jab GPT ne internet, books, code, aur articles se seekha.

Inferencing phase – jab tum use use kar rahe ho aur wo answers de raha hai.

Hum ChatGPT ko train nahi kar sakte (kyunki ye OpenAI ka private model hai), lekin hum apna chhota model bana sakte hain (open-source wale).

Boss trick – Temperature

Temperature ek setting hai jo GPT ke guessing ka nature badal deti hai:

High temperature → zyada creative, har baar alag jawab

Low temperature → safe and predictable answers

Example:

Low temp: "The sky is blue." (safe)

High temp: "The sky is pink with dancing unicorns!" (creative)

In short

GPT is like ek super-smart storyteller jo tumhare diye huye shabd ke baad wale shabd predict karta hai, aur fir pura jawab bana deta hai. Bas difference yeh hai ki tumhare dimaag me memories hoti hain, aur GPT ke dimaag me billions of tokens ki knowledge hoti hai.

Fun Fact for the 5-year-old you: Jab tum kahoge “Tell me about dinosaurs,” GPT tumhare school book ki tarah facts de sakta hai, aur tumhare bedtime story wali mummy ki tarah fairy tales bhi bana sakta hai.