How Large Language Models Actually Work
Summary
Large Language Models predict text by analyzing patterns in billions of words, using token-based processing and transformer architectures. Though they can mimic fluent language and assist with tasks like writing and coding, they don’t understand meaning. Their value lies in extending—not replacing—human capabilities.
Key insights:
Token-Based Prediction: LLMs break text into tokens and predict the next likely token, building coherent responses from patterns.
Trained on Massive Data: They learn language by processing billions of words, adjusting parameters to refine predictions.
Powered by Transformers: The transformer architecture enables LLMs to manage complex, long-range relationships in text.
Scale Enables Nuance: The more parameters an LLM has, the better it captures subtle context, tone, and associations.
Limits of Understanding: LLMs simulate knowledge but don’t reason, feel, or comprehend like humans.
Human Oversight is Essential: LLMs can assist and accelerate tasks, but human judgment ensures accuracy and ethical use.
Introduction
Artificial Intelligence (AI) has become one of the most talked-about technologies of our time. Every week, headlines trumpet breakthroughs, controversies, or bold predictions about how AI will reshape the world. At the center of this conversation are Large Language Models (LLMs), systems like GPT, Claude, and others that can generate text, answer questions, and even write code.
But here is the problem: most explanations of LLMs swing between extremes. Some are drenched in technical jargon that only machine learning engineers can parse. Others are so simplified that they border on science fiction. What’s missing is a straightforward, no-hype explanation that helps the average person understand what these models actually do, how they work, and why they matter.
That is what this insight aims to deliver. Think of it as a guided tour: we will strip away the buzzwords, avoid the hype, and walk step by step through the mechanics of LLMs in plain English.
What Is a Large Language Model?
At its core, a Large Language Model (LLM) is a computer program trained to predict words. That is it, but the simplicity of that statement hides enormous complexity.
Imagine you are texting a friend, and your phone suggests the next word. If you type “I am going to the…”, your phone might suggest “store” or “gym.” That is a tiny version of what LLMs do. They look at the words you have already written and guess what comes next.
The difference is scale. Instead of being trained on a few text messages, LLMs are trained on billions of words from books, articles, websites, and conversations. This massive training allows them to generate text that feels fluent, coherent, and surprisingly human-like.
What makes LLMs remarkable is not just their ability to predict words, but the way those predictions can be strung together into essays, stories, explanations, or even computer code. They do not know language the way humans do, but they have absorbed enough patterns to mimic fluency across countless topics.
In short, an LLM is like a supercharged text predictor, one that has read more than any human could in a lifetime, and can use that exposure to generate responses that feel natural and informed.
The Building Blocks: Tokens
To understand how LLMs work, we need to talk about tokens.
A token is a chunk of text. It might be a whole word (“cat”), part of a word (“ing”), or even punctuation (“?”). LLMs do not see text the way we do; they break everything down into tokens, because working with smaller pieces makes language easier to process mathematically.
When you type a sentence into an LLM, it converts your words into tokens, processes them, and then predicts the next token. Piece by piece, it builds an answer.
Think of tokens as Lego bricks. Each brick is small and simple, but when you stack millions of them together, you can build something complex, like a castle or a spaceship. In the same way, LLMs build sentences, paragraphs, and essays out of tokens.
This token-based approach also explains why LLMs sometimes stumble. If they misplace a brick, the structure of the sentence can wobble. But when they get it right, the result feels seamless, as though the words were chosen with human intuition.
Understanding tokens is crucial because it shows us that LLMs do not process ideas or meanings directly. They process patterns of symbols, and from those patterns, they generate text that looks meaningful to us.
The Training Process
Here is where things get interesting. How does an LLM learn to predict tokens so well?
The answer lies in training. During training, the model is fed enormous amounts of text. It reads through this data and tries to guess the next token. If it guesses wrong, it adjusts its internal settings slightly. Over billions of guesses, it gets better and better.
This process is called machine learning. Specifically, LLMs use a technique called deep learning, which involves artificial neural networks, computer systems inspired (loosely) by the human brain.
The key idea: the model does not memorize text. Instead, it learns patterns. It notices that “peanut butter” is often followed by “and jelly.” It sees that “once upon a time” usually starts a story. Over time, it builds a statistical map of language.
The Transformer Architecture
Now we get to the heart of LLMs: the transformer.
Introduced in 2017, transformers revolutionized AI. Before transformers, models struggled to handle long sentences or complex relationships between words. Transformers solved this by introducing a mechanism called attention.
Attention allows the model to focus on the most relevant parts of a sentence. For example, in the sentence “The cat that chased the mouse was hungry,” attention helps the model understand that “cat” is the subject of “was hungry,” not “mouse.”
This ability to track relationships across long stretches of text is what makes transformers so powerful. It’s why modern LLMs can write essays, summarize articles, or hold conversations without losing track of context.
Scale Matters
Why are these models called large? Because in the world of language models, size truly matters.
LLMs are trained with billions or even trillions of parameters. Parameters are the adjustable settings inside the model, like knobs on a giant control panel. Each parameter helps the model fine‑tune its predictions, shaping how it interprets patterns in text. The more parameters a model has, the more nuanced its grasp of language becomes.
Think of parameters as the resolution of a photograph. A low‑resolution image might give you the general outline of a face, but the details are blurry. A high‑resolution image, by contrast, reveals fine textures. In the same way, a small model might recognize that “Paris” is a city, while a large model can connect Paris to its role as the capital of France, its landmarks like the Eiffel Tower, and its cultural reputation for romance.
This scale allows LLMs to capture subtle connections and cultural knowledge that smaller models would miss. It is the difference between a dictionary that only defines words and an encyclopedia that explains how those words fit into history and society.
What LLMs Can and Can’t Do
It is tempting to think of Large Language Models as intelligent. After all, they can produce essays, answer questions, and even mimic human conversation with remarkable fluency. But here’s the truth: while they appear smart, they don’t actually think, reason, or understand the way humans do. Their strength lies in recognizing and reproducing patterns in language, not in genuine comprehension.
What They Can Do
Generate fluent text in many styles: LLMs can write in formal, casual, poetic, or technical tones. They can draft emails, compose stories, or even mimic the style of a particular author.
Summarize information quickly: Given a long article or report, they can condense it into a digestible summary, saving time for readers.
Translate between languages: They can convert text across dozens of languages, often with impressive accuracy, making communication more accessible.
Write code or explain technical concepts: Developers use LLMs to generate snippets of code, debug errors, or explain programming concepts in plain language.
Assist with brainstorming and creativity: Whether it is product names, marketing slogans, or plot ideas for a novel, LLMs can spark inspiration by offering diverse suggestions.
These capabilities make LLMs powerful assistants in everyday tasks, from business productivity to creative exploration.
What They Can’t Do
Truly understand meaning: LLMs do not grasp context the way humans do. They do not know what Paris feels like in spring or why a joke is funny, they only reproduce patterns of words that statistically fit.
Verify facts reliably: Because they generate text based on patterns, they sometimes produce information that sounds plausible but is false. This phenomenon is called hallucination. Without external fact-checking, their outputs can mislead.
Feel emotions or intentions: LLMs do not experience joy, sadness, or empathy. They can mimic emotional language, but it’s simulation, not genuine feeling.
Replace human judgment in complex decisions: In areas like law, medicine, or ethics, human oversight is essential. LLMs can provide input, but they lack the moral compass and contextual awareness needed for responsible decision-making.
The Bottom Line
LLMs are powerful tools, but they’re not magic. They are pattern-recognition machines trained to predict words, not conscious beings with understanding or intent. Their value lies in extending human capability, making tasks faster, easier, and sometimes more creative, but they must be used with care, especially in contexts where accuracy and judgment matter most.
Why This Matters
The hype around AI often paints LLMs as either saviors or threats. Some claim they will replace all jobs; others warn they’ll destroy humanity.
The reality is more grounded. LLMs are tools, impressive ones, yes, but still tools. Like calculators or search engines, they extend human capability. They can make writing faster, coding easier, and research more efficient. But they also require oversight, because they can make mistakes.
Understanding LLMs without hype helps us use them wisely. It prevents blind trust and unnecessary fear.
Everyday Analogies
Sometimes the easiest way to understand Large Language Models is to compare them to everyday experiences. These analogies don’t capture every technical detail, but they help illustrate how LLMs operate in ways that feel familiar.
1. Autocomplete on Steroids
Think about the autocomplete feature on your phone when you’re texting. It looks at the last few words you typed and suggests what might come next. LLMs do the same thing, but instead of being trained on your personal text history, they’ve been trained on vast amounts of text from across the internet. That is why they can finish your sentence not just with “store” or “gym,” but with a whole paragraph that sounds polished and natural.
2. Statistical Weather Forecast
Meteorologists don’t know exactly what the weather will be tomorrow, but they use historical data and current conditions to make predictions. LLMs work in a similar way. They do not know what you’re going to ask next, but they use patterns from billions of examples to predict the most likely words to follow. Just as weather forecasts can be mostly right but occasionally wrong, LLMs can produce fluent answers that sometimes miss the mark.
3. Library Without Librarians
Imagine walking into a massive library filled with millions of books, but there are no librarians to guide you. You can pull books off the shelves and shuffle sentences together, but you do not truly understand the meaning behind them. That’s how LLMs operate. They have read enormous amounts of text, but they don’t comprehend it the way humans do. They can recombine patterns into something that looks insightful, but they don’t have awareness of the ideas themselves.
Together, these analogies remind us that LLMs are powerful but mechanical. They can mimic fluency and provide useful outputs, but they are ultimately prediction engines, tools that extend human capability rather than replacements for human understanding.
The Human Role
Here is the most important part: humans remain central.
Large Language Models can generate drafts, ideas, or explanations, but they do not replace the uniquely human qualities of judgment, creativity, and ethics. A model can suggest a business strategy, but it takes a human leader to weigh risks, consider values, and decide what’s right for their team. A model can draft a poem, but it’s the human poet who infuses it with lived experience and emotion.
Humans also act as filters. LLMs can produce vast amounts of text, but not all of it is accurate or useful. It is up to us to evaluate, refine, and apply their outputs responsibly. In this sense, LLMs are like powerful assistants: they can accelerate the work, but they rely on human oversight to ensure quality and integrity.
The best use of LLMs is collaboration. They are not replacements for human intelligence; they are partners that amplify it. Just as calculators did not eliminate the need for mathematicians but instead freed them to focus on higher-level problems, LLMs free us from repetitive tasks so we can focus on creativity, strategy, and innovation.
The Road Ahead
Where do LLMs go from here? The trajectory is clear, but the details are evolving rapidly.
Smarter Models: Future LLMs will likely be more accurate, less prone to hallucinations, and better at reasoning. Advances in architecture and training methods will help them move beyond surface-level predictions toward deeper contextual understanding.
Specialized Models: Instead of relying on one giant general-purpose model, we will see smaller models fine-tuned for specific domains such as medicine, law, education, finance. These specialized systems will be safer and more reliable because they will be trained with narrower, domain-specific data.
Integration Everywhere: LLMs won’t remain standalone tools. They will be embedded into apps, devices, and workflows, becoming invisible but ubiquitous. Much like search engines today, they will quietly power everyday tasks behind the scenes.
Ethical Challenges: As LLMs spread, issues like bias, misinformation, and privacy will remain critical. Who controls the data? How do we ensure fairness? How do we prevent misuse? These questions will shape the next decade of AI development.
The journey is ongoing, but the direction is unmistakable: LLMs will become part of everyday life, much like smartphones or the internet itself. The challenge is not whether they will be used, it’s how wisely we will choose to use them.
Conclusion
Large Language Models are not mystical beings. They are not conscious, nor are they plotting world domination. They are sophisticated statistical tools that predict words based on patterns in massive datasets.
By stripping away the hype, we see them for what they are: powerful assistants, not replacements for human intelligence.
Understanding how they work, tokens, training, transformers, scale, empowers us to use them wisely. And that is the real insight: the future of AI is not about machines taking over. It is about humans learning to collaborate with machines more effectively.
Build with AI that’s grounded, not hyped.
Walturn helps teams use LLMs responsibly—combining cutting-edge AI with domain expertise for scalable, trusted solutions.
References
Introduction to large language models. (n.d.). Google for Developers. https://developers.google.com/machine-learning/resources/intro-llms
Behind the pipeline - Hugging Face LLM Course. (n.d.). https://huggingface.co/learn/llm-course/chapter2/2
Kaplan, J., McCandlish, S., Henighan, T., Brown, T. B., Chess, B., Child, R., Gray, S., Radford, A., Wu, J., & Amodei, D. (2020, January 23). Scaling laws for neural language models. arXiv.org. https://arxiv.org/abs/2001.08361?utm_source=copilot.com
Alammar, J. (n.d.). The illustrated transformer. https://jalammar.github.io/illustrated-transformer/
Wikipedia contributors. (2025, December 15). Neural network (machine learning). Wikipedia. https://en.wikipedia.org/wiki/Parameter_(machine_learning)
Matsumoto, T., Miura, T., & Yanai, N. (2023). Membership Inference Attacks against Diffusion Models. arXiv.org. https://arxiv.org/abs/2302.03262?utm_source=copilot.com
Bender, E. M., Gebru, T., McMillan-Major, A., & Shmitchell, S. (2021). On the Dangers of Stochastic Parrots. Proceedings of the ACM Conference on Fairness, Accountability, and Transparency (FAccT ’21), 610–623. https://doi.org/10.1145/3442188.3445922
Alammar, J. (n.d.-a). Jay Alammar – Visualizing machine learning one concept at a time. https://jalammar.github.io/?utm_source=copilot.com
Unger, M. (2026, January 9). The role of people in AI-Human teams. Forbes. https://www.forbes.com/councils/forbesbusinesscouncil/2026/01/09/the-role-of-people-in-ai-human-teams/?utm_source=copilot.com














































