How Large Language Models Work in Plain English
You use ChatGPT, Claude, or Gemini nearly every day. They draft your emails, summarize documents, brainstorm ideas, and analyze data. But do you actually understand how they work? Not at the engineering level—you don't need to build one. But at the conceptual level that makes you a smarter, more effective user?
Most business owners treat large language models like magic boxes: put a question in, get an answer out. That approach works until it doesn't—until the model confidently gives you wrong information, misses the point of your request, or produces output that sounds great but says nothing useful.
Understanding the mechanics—even at a high level—transforms how you use these tools. You'll know why certain prompts work better than others, why the model sometimes invents facts, and how to get dramatically better results from the same tool your competitors are using badly.
The Core Idea: Next-Word Prediction at Scale
Strip away all the complexity, and every large language model does one fundamental thing: it predicts the next word.
That's it. When you ask your AI tool "What is the capital of France?", the model doesn't look up the answer in a database. Instead, it calculates the most statistically likely sequence of words to follow your question, based on patterns it learned during training. It generates "The" (most likely first word), then "capital" (most likely next word given what came before), then "of" then "France" then "is" then "Paris"—one word at a time.
This sounds almost too simple to be powerful. But when next-word prediction operates across billions of parameters trained on trillions of words, something remarkable emerges: the system develops what appears to be understanding, reasoning, and creativity—even though it's technically just doing very sophisticated pattern matching.
Why This Matters for You
If you understand that LLMs generate text through prediction rather than retrieval, you'll immediately understand why they sometimes produce incorrect information with total confidence. The model isn't lying—it's generating the most statistically likely text, which usually aligns with truth but sometimes doesn't.
How LLMs Learn: Training Explained Simply
Before an LLM can predict words, it has to learn language patterns. This happens in two phases.
Phase 1: Pre-Training (Reading the Internet)
In the pre-training phase, the model processes an enormous corpus of text—books, websites, research papers, code, forums, and more. During this process, the model isn't memorizing the text. Instead, it's learning statistical relationships: which words tend to follow other words, how sentences are structured, what concepts tend to appear together, and how ideas connect across paragraphs.
Think of it like a new employee who reads every document your company has ever produced before their first day. They don't memorize every sentence, but they develop a deep intuition for how your organization communicates, what topics matter, and how ideas relate to each other.
This phase is what makes LLMs "large"—the models that power your AI tool have hundreds of billions of parameters (the numerical values that encode these learned patterns). Training requires enormous computing resources, which is why only a handful of organizations can build frontier models from scratch.
Phase 2: Fine-Tuning (Learning to Be Helpful)
Raw pre-training produces a system that can predict text but doesn't know how to be a helpful assistant. The second phase—fine-tuning—teaches the model to follow instructions, have conversations, decline harmful requests, and produce useful responses.
This is typically done through a process called RLHF (reinforcement learning from human feedback), where human evaluators rate the model's responses and the model learns to produce outputs that humans find helpful, harmless, and honest.
Fine-tuning is why your AI tool behaves like a helpful assistant rather than randomly completing text. The same base model could generate a poem, write code, or explain quantum physics—fine-tuning is what teaches it to respond appropriately to your specific request.
Tokens: The Language LLMs Actually Speak
LLMs don't actually process words. They process tokens—chunks of text that are roughly three-quarters of a word on average. Common words like "the" are single tokens. Longer or less common words get split: "unbelievable" might become "un" + "believ" + "able."
Understanding tokens matters for three practical business reasons.
Context windows. Every LLM has a maximum number of tokens it can process in a single conversation—its "context window." As of early 2026, leading models handle 100,000 to 200,000 tokens (roughly 75,000-150,000 words). If your conversation exceeds this limit, the model starts "forgetting" earlier parts of the conversation. This is why very long AI sessions can become less coherent over time.
Pricing. API pricing for LLMs is typically per-token. Understanding token counts helps you estimate costs and optimize your usage. A 500-word email is roughly 670 tokens; a 3,000-word report is about 4,000 tokens.
Performance. The more context you provide (more tokens), the better the model understands your request. But there's a practical balance—extremely long prompts can slow response times and increase costs without proportionally improving quality.
Practical Token Math for Business
1 token 0.75 words (or 4 characters in English). A typical business email (200 words) 270 tokens. A one-page document (500 words) 670 tokens. A full-length report (5,000 words) 6,700 tokens. Most business tasks comfortably fit within modern context windows.
Why LLMs Hallucinate—And What to Do About It
The single most important thing to understand about LLMs is why they sometimes generate false information—a phenomenon called "hallucination."
Remember: LLMs generate text by predicting what words are most likely to come next. Usually, the most likely continuation is also the correct one. When you ask about the capital of France, the training data overwhelmingly associates "capital of France" with "Paris," so the prediction is accurate.
But what happens when you ask about something obscure, highly specific, or recent? The model still generates the most statistically likely continuation—but with less data to anchor the prediction, it may produce something that sounds perfectly plausible but is factually wrong. The model doesn't know it's wrong because it doesn't have a concept of "knowing." It only has statistical patterns.
When Hallucinations Are Most Likely
You're at higher risk of getting hallucinated content when asking about very specific facts (exact dates, statistics, quotes), recent events (after the model's training data cutoff), niche or specialized topics with limited training data, or requests that combine real elements in novel ways the training data doesn't cover.
How to Protect Your Business
Hallucination is a feature of the technology, not a bug that will be fully fixed. Smart users work with this reality rather than against it.
The Verification Framework
Always verify facts. Use LLMs for drafting, brainstorming, and analysis, but independently verify any specific claims, statistics, or facts before using them in business decisions or public communications.
Use the right tool for the right job. LLMs excel at generating text, analyzing patterns, and reasoning through problems. They're not databases. For factual lookups, use actual databases.
Ask for sources. When an LLM cites a study or statistic, ask for the specific source. If it can't provide a verifiable citation, treat the claim as unverified.
Cross-check with multiple approaches. For important decisions, ask the model to argue the opposite position, or rephrase your question to approach it from a different angle. If the answers contradict each other, dig deeper.
Temperature: Controlling Creativity vs. Consistency
When an LLM predicts the next word, it doesn't always choose the single most likely option. A setting called "temperature" controls how much randomness the model introduces into its word selection.
Low temperature (0 to 0.3) makes the model almost always choose the most probable next word. The output is consistent, predictable, and conservative. This is ideal for factual content, data analysis, and business documents where accuracy matters more than creativity.
Medium temperature (0.4 to 0.7) introduces some variation. The model might choose the second or third most likely word occasionally, producing more natural-sounding text with slight variations in phrasing. This works well for email drafting, general content creation, and conversational responses.
High temperature (0.8 to 1.0+) allows significant randomness. The model explores less probable word choices, producing more creative and surprising output—but also increasing the risk of incoherence or hallucination. This is useful for brainstorming, creative writing, and generating novel ideas.
| Use Case | Recommended Temperature | Why |
|---|---|---|
| Financial reports, contracts | Low (0 - 0.2) | Maximum accuracy and consistency |
| Customer emails, blog posts | Medium (0.4 - 0.6) | Natural tone without excessive risk |
| Marketing taglines, brainstorming | Higher (0.7 - 0.9) | Creative variation and novel ideas |
| Data extraction, classification | Very low (0) | Deterministic, repeatable results |
Not every tool exposes temperature settings directly. your AI tool and Claude's web interfaces handle this automatically. But if you use the API or advanced settings, understanding temperature gives you fine-grained control over output quality.
The Practical Implications for Business Users
Now that you understand the mechanics, here's how this knowledge changes your daily use of AI tools.
Better Prompts Come from Understanding Prediction
Because LLMs predict text based on context, the more relevant context you provide, the better the prediction. A prompt like "Write a marketing email" gives the model almost nothing to work with—it'll generate something generic. But "Write a marketing email for our B2B SaaS product that helps accounting firms automate their monthly close process. The audience is CFOs at firms with 50-200 employees. Tone should be professional but not stuffy. Include a specific benefit about reducing close time by 40%" gives the model rich context that guides its predictions toward exactly what you need.
This isn't about tricking the model. It's about giving the prediction engine the raw material it needs to predict correctly.
Conversations Have Memory (With Limits)
Within a single conversation, everything you've said becomes part of the context that the model uses for predictions. This is why follow-up questions work—the model can reference what you discussed earlier. But this context has limits (the context window), and in very long conversations, the model may lose track of earlier details.
For complex business tasks, consider starting fresh conversations for distinct topics rather than cramming everything into one long thread. Each new conversation resets the context, allowing the full context window to be dedicated to your current task.
The Model Doesn't Know What It Doesn't Know
Perhaps the most important insight: LLMs have no internal mechanism for uncertainty. When a human doesn't know something, they feel uncertain and might say "I'm not sure." When an LLM encounters a topic outside its strong training data, it still generates the most probable text—which may include confident-sounding statements about things it effectively "doesn't know."
Some models (like your AI tool) have been specifically trained to express uncertainty and say "I don't know" more often. But the fundamental limitation remains. As a business user, you should always maintain a healthy verification habit, especially for specific facts, numbers, and claims.
Key Takeaway
Large language models are sophisticated prediction engines. They generate text one word at a time by calculating statistical probabilities based on patterns learned from massive training datasets. This makes them extraordinarily useful for drafting, analyzing, and reasoning—but it also means they can generate plausible-sounding falsehoods. The business user who understands this produces better prompts, verifies critical information, and gets dramatically more value from the same tools everyone else has access to.
What You'll Learn Next
You now understand how the most important AI technology works. In the next lecture, , we'll catalog the entire landscape of AI tools relevant to business—from text generation to image creation to data analysis—so you know exactly what's available and what each category is best suited for.
Frequently Asked Questions
How do large language models like your AI tool actually work?
LLMs work by predicting the most likely next word (technically, next token) in a sequence. They were trained on vast amounts of text and learned statistical patterns about language. When you provide a prompt, the model generates a response one token at a time, each prediction informed by everything that came before it in the conversation. The result appears intelligent because the statistical patterns encode real-world knowledge and reasoning structures.
Why do AI models sometimes make up information?
LLMs generate the most statistically likely text continuation, not verified facts. When the model encounters topics where its training data is thin or ambiguous, the most likely text may still sound confident and plausible while being factually incorrect. The model has no internal mechanism for distinguishing "I know this" from "this sounds right." Always verify specific facts, statistics, and claims independently.
What is a context window and why does it matter?
A context window is the maximum amount of text an LLM can process in a single conversation—including both your messages and the model's responses. Leading models in 2026 support 100K-200K tokens (roughly 75,000-150,000 words). When a conversation exceeds this limit, the model begins losing access to earlier messages. For long or complex tasks, consider starting fresh conversations or providing the most critical context in each new message.
What does temperature mean for AI-generated content?
Temperature controls how creative versus predictable an LLM's output is. Low temperature (0-0.3) produces consistent, accurate text ideal for business documents. Medium temperature (0.4-0.7) adds natural variation for emails and content. High temperature (0.8+) enables creative, surprising outputs useful for brainstorming. Most consumer AI tools manage temperature automatically, but API users and advanced features often let you adjust it directly.
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