Large Language Model (LLM)

What is a Large Language Model (LLM)?

A Large Language Model (LLM) is a type of artificial intelligence system trained on vast quantities of text data to understand and generate human language. LLMs are the technology underpinning the AI tools that e-commerce operators interact with daily: ChatGPT, Claude, Gemini, and Copilot are all LLM-powered interfaces. When a marketer uses AI to write a product description, draft a campaign brief, or answer a question about their analytics data, they are interacting with an LLM.

For e-commerce practitioners who are not engineers, understanding LLMs at a conceptual level matters because it determines how effectively you can use and direct these tools. LLMs work by predicting the most statistically likely continuation of a given input - which means their output quality is directly proportional to the specificity and context of what you give them. A prompt that says 'write a product description for a face serum' will produce generic output. A prompt that provides the product's hero ingredient, the target customer, the brand's tone of voice, three competitor descriptions to differentiate from, and the SEO keyword to include will produce something commercially useful. This is the foundation of prompt engineering - the skill of structuring inputs to get high-quality outputs from LLMs.

LLMs are also the engine behind the AI agents reshaping how consumers shop and how merchants operate. When a shopper's AI assistant researches products on their behalf, or when an AI agent inside Shopify executes a multi-step merchandising workflow, an LLM is doing the reasoning. Understanding that LLMs are probabilistic, context-sensitive, and only as current as their training data helps e-commerce teams use them more effectively and avoid over-relying on them in contexts that require real-time data or absolute accuracy - like live inventory levels or dynamic pricing.