What is a Large Language Model (LLM)? Starting from Scratch

Welcome, class! We're kicking off our 10-module adventure to transform you into AI-native software engineers. Whether you're a complete beginner or just dipping your toes into machine learning, this course is designed for you—no prior knowledge required. We'll start from the absolute basics and build step by step, using simple analogies to make everything click. By the end, you'll be ready to harness Large Language Models (LLMs), build AI agents, and wield tools like Claude Code with confidence.

Think of this module as laying the foundation for our rocket ship. Before we blast off, we need to understand what the engine is and why it's revolutionary. We'll explore what an LLM really is, how it works at its core, and why it's a game-changer for folks like you who want to build the future of software. Let's dive in, nice and slow!

What is a Large Language Model (LLM)? Starting from Scratch

If you've never heard of an LLM before, don't worry—we're starting from zero. Imagine language as the ultimate puzzle: words fitting together to create meaning. An LLM is like a super-smart puzzle solver trained on billions of these puzzles.

From first principles:

• The Basics: An LLM is a type of artificial intelligence model designed to handle human language. It's "large" because it's built with billions (or even trillions) of parameters—think of these as tiny knobs that get tuned during training to recognize patterns in text.
• How It Starts: These models are trained on massive datasets: books, websites, articles—pretty much the entire internet's worth of words. The goal? Learn the rules and quirks of language.

Analogy Time: Picture an LLM as a "universal apprentice" who's read every book in the world's biggest library. This apprentice doesn't truly "understand" like a human, but it's memorized so many patterns that when you ask, "How do I bake a cake?" it can spit out a perfect recipe, step by step. It's not magic—it's statistics on steroids!

Quick Check-In: If this is your first encounter with AI, just remember: LLMs are tools that process and generate text based on patterns they've seen. No deep math yet—we'll build to that gradually.