What AI Actually Is

Separate artificial intelligence, machine learning, and large language models, and understand what these systems do rather than what they appear to do.

By the end of this lesson you can

  • Distinguish AI, machine learning, and large language models
  • Explain in plain terms how a language model produces text
  • Describe what training data is and why it determines a model's limits
  • Explain why these systems are delivered as cloud services
📘 Reading Lesson

Lesson Notes

Read through the key concepts before you try the challenge.

Three words that are not synonyms

On the job

You evaluate a vendor's claims at Lakeside Medical Associates.

A scheduling vendor says its product is 'AI-powered.' That could mean a large language model reading appointment requests, a statistical model predicting no-shows, or a set of if-then rules someone wrote in 2015. All three are marketed the same way, and they carry very different risks.

Your task: Understand the terms precisely enough to ask a vendor what their product actually does.

Key terms

Artificial intelligence
The broad field of building systems that perform tasks normally requiring human intelligence. An umbrella term, not a specific technology.
Machine learning
A subset of AI where a system learns patterns from data rather than following rules a person wrote. The system is trained, not programmed.
Large language model (LLM)
A machine learning model trained on very large amounts of text to predict likely continuations. ChatGPT, Claude, and Gemini are LLM-based products.
Training data
The material a model learned from. It determines what the model knows, what it is good at, and which biases it carries.
Generative AI
Models that produce new content — text, images, code — rather than only classifying or predicting.
Prompt
The input you give a model. With generative systems, the quality of the prompt substantially determines the quality of the output.

A large language model works by predicting likely next words, over and over, given everything before them. That description sounds reductive, and it genuinely is how these systems operate. The output is fluent because the patterns it learned are fluent — not because the system checked whether the content is true.

This is the single most important fact about these tools: a language model optimizes for plausible text, not for accurate text. It has no mechanism that distinguishes a fact it learned from a fluent invention. When it states a drug interaction, a policy citation, or a date with total confidence, that confidence carries no information about whether the statement is correct. Everything in the next lesson about verification follows from this.
TypeGood atPoor at
Rule-based systemConsistent, auditable decisions with known logicAnything its author did not anticipate
Machine learning classifierPredicting categories from many examples — spam, no-show riskExplaining why; handling cases unlike its training data
Large language modelDrafting, summarizing, rephrasing, explainingFacts, arithmetic, citations, anything needing to be verifiably true
What each kind of system is suited to

These models are delivered as cloud services for a straightforward reason: training and running them requires hardware far beyond a workstation. This is the IaaS/PaaS/SaaS stack from Module 2 in its newest form — you consume AI as SaaS, over the internet, with all the shared-responsibility implications that carries. Your prompt leaves your building.

Check your understanding

An AI assistant states a specific drug interaction with complete confidence. What does that confidence tell you about the accuracy of the claim?

Challenge

Apply what you've learned in this lesson.

Test the claim rather than accepting it.

  1. Ask a free AI assistant a factual question in an area you know well. Assess the answer for accuracy and note anything subtly wrong.
  2. Ask it for three sources supporting a claim. Attempt to locate each one. Record how many actually exist.
  3. Ask the same question three times in separate conversations. Compare the answers and note where they differ.
  4. Write a paragraph explaining to a colleague why 'it sounded very confident' is not evidence that an AI answer is correct.

Finished this lesson?

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