What is AI (and what it is not)
Machine learning vs deep learning vs generative AI — vocabulary, limits, and when not to use an LLM.
Why this article exists
Andrew Ng’s AI for Everyone starts with terminology and limits. ShipAI engineers still need that bridge: stakeholders say “AI” when they mean a spreadsheet rule, a classifier, or ChatGPT. This page is the shared vocabulary before tokens and transformers.
Misnaming the problem causes bad architecture: teams buy an LLM for a deterministic eligibility rule, or train a custom model when a prompt + retrieval would ship in a week.
Three nested ideas
flowchart TD
AI[Artificial intelligence] --> ML[Machine learning]
ML --> DL[Deep learning]
DL --> Gen[Generative AI / LLMs]
| Term | Plain meaning | Typical artifact |
|---|---|---|
| AI | Systems that perform tasks that look intelligent | Broad product label |
| ML | Learn patterns from data instead of hand-coded rules | Classifier, ranker, forecaster |
| Deep learning | ML with multi-layer neural nets | Image net, speech model, LLM |
| Generative AI | Models that produce new text/images/code/audio | Chatbots, copilots, image tools |
Ship rule: Prefer the most specific true label. Calling everything “AI” hides whether you need labeled data, a retrieval index, or just better UX.
Narrow vs general (product language)
| Phrase | Useful meaning | Trap |
|---|---|---|
| Narrow AI | Good at a scoped task (spam, ranking, extract fields) | Sounds “small” — can still be critical path |
| General / frontier models | Broad skills via large pretrained LLMs | Not automatically correct on your facts |
| AGI | Speculative human-level generality | Not a shipping milestone for your roadmap |
Build products with narrow success metrics, even when the engine is a general model.
What today’s LLMs are good at
- Drafting, summarizing, transforming text and code
- Tool-using agents when tools are reliable and scoped (Agents and ReAct)
- Retrieval-augmented Q&A over your docs (with evals) (RAG building blocks)
- Structured extraction when schemas are validated (Structured outputs)
- Classification / routing when a golden set says they beat a baseline
What they are bad at (without extra systems)
- Guaranteeing facts without retrieval or tools
- Exact arithmetic / inventory counts (use code tools)
- Fresh private knowledge not in context or an index
- Decisions that require auditability and zero hallucination risk alone
- Long-horizon autonomy without stop policies and HITL
flowchart TD
Job[Job to be done] --> Q1{Need creativity / language?}
Q1 -->|No| Rules[Rules / SQL / classic ML]
Q1 -->|Yes| Q2{Need private facts?}
Q2 -->|Yes| RAG[RAG / tools]
Q2 -->|No| LLM[LLM prompt]
RAG --> Eval[Eval gate]
LLM --> Eval
Rules --> Ship[Ship]
Eval --> Ship
Supervised, unsupervised, reinforcement (one slide)
- Supervised — learn from input→label pairs (spam / not spam)
- Unsupervised — structure without labels (clustering, embeddings)
- Reinforcement — learn from rewards (RLHF for preference alignment)
LLMs use all three across their lifecycle: unsupervised-ish pretrain on text, supervised fine-tunes, preference/RL stages. Product engineers mostly touch the last mile: prompts, RAG, light fine-tunes, and evals — see LLM project lifecycle.
When not to use an LLM
| Situation | Prefer |
|---|---|
| Deterministic policy (“if amount > X”) | Rules engine |
| Stable labels + tabular features | Classical ML (Classical ML literacy) |
| Exact counts / money math | Code / DB aggregates |
| Need citations to private docs | RAG + citations, not “just ChatGPT” |
| Regulated decision with hard audit | Human + constrained tools; not free-form generation alone |
Failure modes of “AI” projects
| Failure | What it looks like | Fix direction |
|---|---|---|
| Solution looking for a problem | Cool demo, no metric | Write success metric first |
| Wrong tool | LLM for eligibility rules | Rules / workflow |
| No evals | “Looks good in Slack” | Golden set + gate |
| Data denial | Want magic without corpus or labels | Scope to prompt-only or collect data |
| Overclaim | Marketing says “accurate” | Measure faithfulness / task success |
Glossary
| Term | Meaning |
|---|---|
| Model | Learned function mapping inputs → outputs |
| Inference | Running a trained model on new inputs |
| Hallucination | Fluent output not grounded in facts/evidence |
| Baseline | Simple system you must beat on metric + cost |
Micro-project
List three work problems that are ML, three that are rules, and three that should not use AI. For one ML candidate, write a one-line success metric.
Related guided path
What happened in AI (till now) and ML/DL literacy. Next Core Concepts: Classical ML literacy, then Tokenization.