What Is an LLM? The AI Behind ChatGPT, Google AI, and Business Recommendations
Large Language Model (LLM) – A type of AI trained on vast amounts of text that powers tools like ChatGPT, Google AI, and Perplexity, and increasingly shapes how people discover and choose businesses.
LLM stands for Large Language Model, and it’s the technology that sits inside ChatGPT, Google AI, Perplexity, and every other AI tool that people now use to find businesses. When someone types “best plumber in Austin” into ChatGPT, an LLM is what reads the question, pulls together everything it knows, and writes the recommendation. It’s the thing deciding which businesses get named and which ones get left out.
The practical question for any business owner is: what does this thing know about my business, and where does it get its information? The answer is the open web. LLMs are trained on billions of pages of text, including business websites, review platforms, directories, news articles, and forum posts. On top of that, modern AI tools like ChatGPT can also search the web in real time before answering. So the information about a business that exists online, across all platforms, is exactly what the LLM is working with when it decides whether to mention that business to a potential customer.
This is why AI visibility is so closely tied to online presence. A business described in detail across five or six independent platforms gives the LLM much more to work with than one that only has a website and a Google Maps listing.
One thing that surprises people is how different the answers are across platforms. We compared pizza recommendations in NYC and found that ChatGPT and Google AI named completely different winners for the same question. That happens because each platform runs a different LLM, trained on different data, at different points in time. A business that was well-represented online when one model’s training data was collected might have had less presence when another model was trained six months earlier.
The good news is that LLM-based products increasingly search the web in real time, which means improving a business’s online presence today can affect recommendations fairly quickly. The practices behind GEO are essentially about making sure the LLM has enough accurate, detailed, consistent information to confidently recommend a business when someone asks.
Frequently Asked Questions
What's the difference between an LLM and ChatGPT?
An LLM is the underlying technology. ChatGPT is a product built on top of one. Similarly, Google AI runs on the Gemini LLM, and Perplexity uses its own combination. The LLM does the language processing, the product wraps it in an interface and connects it to the web.
Do LLMs search the internet in real time?
Base LLMs work from their training data alone. But products like ChatGPT and Google AI can trigger a web search before generating a response, combining the model's language abilities with fresh information. This means a business that improves its online presence today can start appearing in AI answers relatively quickly.
Can a business influence what an LLM says about it?
There's no paid placement or ad system inside LLM responses. But the information available about a business online is exactly what the model draws from. A detailed, consistent presence across multiple platforms gives the model more to work with when deciding whether to recommend someone.
Does ChatGPT recommend your business?
Enter a website URL. Reachd checks how ChatGPT responds to real customer queries and shows a visibility score in about 30 seconds.