When someone asks ChatGPT or another AI tool a question, the answer doesn’t come out of thin air. These tools are not thinking like humans. They don’t have opinions, and they don’t truly understand the world. What they do have is access to a huge amount of written information—and they use that to build answers.

To understand how Generative Engine Optimization (GEO) works, we first need to understand where generative AI gets its information. 

There are four main sources:

1. Model Training

Every AI tool is trained on large collections of text. This includes books, articles, websites, public forums, manuals, product reviews, and more. Some of this training data is public, and some may come from licensed sources. During training, the AI doesn’t memorize websites—it learns patterns in how people write, explain, and answer questions.

This training gives the AI a general understanding of the world, but it is not always up to date. For example, if the AI was trained on data from 2022, it might not know about a product launched in 2024—unless it also has access to live data.

2. Live Search (Retrieval)

Some tools—like Perplexity, Google Gemini, and ChatGPT with browsing turned on—can perform real-time searches. They look at current websites, articles, and product pages to find the most recent or relevant information. When AI tools do this, they often pull from top-ranked Google results, so traditional SEO still matters.

This process is called retrieval. The AI retrieves information from the internet, summarizes it, and presents it in a new format. This is where GEO becomes important. If your content is clear, structured, and written in a way the AI can use, it may be chosen for the answer.

3. Plugins and Extensions

Some AI tools connect to other services using plugins or extensions. For example, a travel plugin might pull hotel prices from a booking site, or a medical plugin might use a trusted health database. These are limited to specific tasks, but if you work in an industry with plugins, your content could be pulled in if you’re listed in the source site.

4. APIs and Data Feeds

AI tools can also connect directly to data sources using APIs. For example, if an AI tool is connected to a product database, it may use that to answer questions about prices, ingredients, or features. Some companies pay to feed their data into these systems.

AI tools do not treat all sources equally. They tend to prefer:

• Well-known websites
• Trusted review platforms
• High-ranking search results
• Clear, well-written content

In other words, the quality and structure of your content still matters. And the more places your brand shows up—in reviews, forums, articles, and search results—the more likely AI tools are to use your content when creating answers.

In the next lesson, you’ll learn what makes a source “AI-friendly”—and how to position your content to be chosen more often.