understanding large language models (LLMs): A comprehensive overview

Large language models (LLMs) have become one of the most exciting advancements in artificial intelligence. These models are changing the way people and businesses interact with technology, making it possible for machines to understand, generate, and even reason with human language.

But what exactly is a large language model? How do they function, and why do they matter so much? In this article, we’ll explore the fundamentals of these transformative models and uncover what the future holds for this groundbreaking technology.

what exactly is a large language model?

A large language model (LLM) is an advanced form of artificial intelligence capable of understanding and generating language at scale. These models go beyond interpreting just English or Mandarin. In today’s context, “language” includes a broad spectrum of human and symbolic communication, everything from mathematical equations and genetic code to sign language, musical notation, programming languages, and even body language.

LLMs are trained on enormous datasets and billions of parameters, allowing them to recognise patterns, learn context, and predict what comes next in each sequence. This enables them to generate coherent responses, hold conversations, write content, summarise information, and assist in code development.

Leading LLMs are already integrated into countless business applications, from automating customer support and accelerating content creation to streamlining financial analysis and improving accessibility.

how do large language models work?

LLMs are built using a combination of neural networks and machine learning that allows them to understand and generate human-like language. Here’s how they work, step by step.

1. training on massive data

LLMs are trained on enormous volumes of text, books, articles, websites, code, and more. This helps them learn language structure, context, tone, and specialised vocabulary across domains.

2. neural networks and pattern recognition

At the heart of an LLM is a neural network, which processes and learns from this data by identifying patterns. As it encounters more data, the model becomes better at understanding how words and ideas connect.

3. machine learning for prediction

Machine learning allows the model to predict what comes next in a sequence of text. By repeatedly predicting the next word based on previous words, the model learns to generate fluent, meaningful responses.

4. transformer architecture

Most LLMs rely on a structure called a transformer, which helps the model weigh the importance of different words in a sentence. This enables it to handle long inputs and generate highly relevant, contextual outputs.

5. fine-tuning for specific tasks

After initial training, LLMs can be fine-tuned on specific data, such as legal contracts or customer service conversations, to make them more effective for particular use cases.

6. real-time response

When you ask a question, an LLM generates a response in real time. It doesn’t retrieve information from a database, instead, it predicts each word based on your prompt and its training.

A note on originality and oversight: While LLMs can produce original, high-quality content, output quality varies based on training data, prompt design, and task complexity. Human oversight is essential for accuracy, ethics, and context, especially in high stakes use cases.

 

why are large language models important?

LLMs are transforming the way we work, learn, and interact, especially in complex, data-driven industries. Their impact is broad and transformative:

Efficiency - LLMs automate tasks like summarising reports, drafting emails, and analysing documents, speeding up workflows.

 

Accessibility - By simplifying complex topics, LLMs empower non-experts to understand and use information, democratising access to knowledge.

 

Innovation - With routine work handled, teams can focus on strategy, creativity, and personalised solutions.

 

User Experience - LLMs enhance interactions with instant, context-aware responses, improving customer service and bridging language gaps in global markets.

 

Scalability - From parsing medical research to interpreting legal contracts, LLMs offer speed, scale, and adaptability.

 

are there risks or limitations?

Like all technology, LLMs come with risks. It’s important to understand what they can and can’t do.

  • Bias and ethical issues: Models may replicate harmful stereotypes found in training data. Preventing harmful, biased, or unsafe outputs is critical, especially in sensitive domains like healthcare or finance.
  • Misinformation: LLMs can “hallucinate” facts, generating plausible but false content.
  • Security and privacy: Mishandling sensitive data can lead to privacy violations.
  • Dependency risks: Overreliance on LLMs can reduce critical thinking or introduce automation errors.
  • Currentness: Models trained on older data may provide outdated answers unless updated or connected to real-time sources.
  • Context awareness: LLMs must be fine-tuned to understand specific business or industry contexts, which can require additional effort.
  • Regulatory uncertainty: AI policy is still evolving. The Organisation for Economic Co-operation and Development (OECD) guidance urges firms to adopt internal governance frameworks and transparency tools while regulations catch up.
Ongoing research is addressing these challenges, and each new model version brings improvements in accuracy, safety, and transparency.

the next wave of LLMs

Enterprise adoption of large language models (LLMs) is accelerating, driven by expanding use cases and smarter strategies. Hybrid approaches blending proprietary and open-source models are now preferred by 37% of organisations for their flexibility and customisation potential. As LLMs go mainstream, enterprises are shifting from experimentation to strategic implementation.

A 2025 study shows 72% of companies are increasing their LLM budgets, with nearly 40% investing over $250,000 annually. Many are opting for paid, enterprise-grade models over free alternatives due to better security, reliability, and support. While challenges like data privacy and rising costs persist, 82% of decision-makers believe generative AI will boost productivity and innovation rather than replace jobs.

Looking ahead, the future of LLMs lies in greater efficiency, multimodal capabilities, and real-time learning. Models will integrate text, images, and audio, become more energy-efficient, and continuously adapt to new data, unlocking deeper business value.

build vs. buy: why some enterprises create custom LLMs

While most organisations adopt pre-trained LLMs from providers like OpenAI or Google for speed and cost efficiency, others are building custom models for greater control and competitive differentiation.
Why build your own?

  • Data sovereignty and security: Custom LLMs allow enterprises to keep sensitive data in-house, ensuring better compliance with data privacy and industry regulations.
  • Cost control at scale: For companies with heavy or specialised usage, custom LLMs can lower long-term costs by optimising compute and retraining cycles.
  • Tailored performance: By training models on proprietary datasets and workflows, businesses can achieve higher accuracy and relevance in domain-specific tasks.
This build-versus-buy decision hinges on factors like data sensitivity, model complexity, and organisational maturity in AI.

how can Infosys BPM help?

As models continue to evolve, they will play an even larger role in everything from finance and education to healthcare and beyond. Infosys BPM can help evaluate the right LLM approach based on your business goals and AI readiness. Take a look at how Infosys BPM helps enterprises harness the full potential of large language models, securely, responsibly, and at scale, to drive intelligent operations and unlock real business value.