LLM – Large Language Model #
Large Language Models (LLMs) are advanced AI systems designed to process, understand, and generate human-like text.
They learn language by analysing massive amounts of text data, discovering patterns in:
grammar
meaning
context
relationships between words and sentences
Built on Deep Learning
Implemented using Neural Networks
Based on Transformers
Often combined with tools like:
- Retrieval (RAG)
- Agents
- External APIs
- Memory systems
What makes an LLM special? #
- Built using deep neural networks
- Trained on very large datasets (books, articles, code, web text)
- Can perform many tasks without task-specific training
- General-purpose language understanding, not single-task models
Foundation: Transformer Architecture #
LLMs are based on the Transformer Architecture, which allows models to understand context and long-range dependencies in text.
Instead of reading text one word at a time, Transformers:
- Look at all words in a sentence at once
- Decide which words are important to each other
- Use attention mechanisms to build meaning
flowchart LR
A[Input Text] --> B[Tokenizer]
B --> C[Transformer Layers]
C --> D[Contextual Representation]
D --> E[Next Token Prediction]
E --> F[Generated Text]
- Text is converted into tokens
- Tokens pass through multiple Transformer layers
- Each layer refines understanding of context
- Model predicts the most likely next token
- Repeating this generates fluent text
Popular LLMs #
- GPT family (OpenAI)
- BERT (Google)
- LLaMA (Meta)
- PaLM / Gemini (Google)
- Claude (Anthropic)
(Exact implementation details differ, but the core ideas remain the same.)
What Can LLMs Do? #
- Text generation and summarisation
- Question answering
- Chatbots and virtual assistants
- Code generation and explanation
- Translation
- Document analysis
- Search and retrieval augmentation (RAG)
Why LLMs Are Powerful #
- Understand context, not just keywords
- Can generalise across many tasks
- Reduce need for task-specific models
- Learn representations automatically
- Scale well with more data and compute
Limitations & Challenges #
- Very large computational and memory cost
- Can produce confident but incorrect answers (hallucinations)
- Lack true understanding or reasoning
- Sensitive to training data quality
- Hard to interpret internally
- Ethical and bias concerns
LLMs do not understand meaning like humans.
They predict the next most likely token based on patterns in data.
An LLM is a very large neural network trained to predict the next word — and becomes powerful by doing this extremely well.