AI Basics Everyone Should Know: What Are Generative AI, LLMs and Machine Learning?

Admin Rock · 2026-10-27 · upskilling

AI, machine learning, deep learning, LLMs and generative AI explained simply, with key terms, cautions and a 4-week learning plan for beginners.

In a meeting someone says, We will use an LLM to do RAG on our company documents. Everyone nods, but half the room is not sure what it means. If you have been there, this article can help. You do not need to be an engineer or data scientist. Understanding a few key terms is enough to read the news, choose tools and talk with your tech team far more confidently.

What is AI?

AI (Artificial Intelligence) is the broadest umbrella term: computer systems that do work normally requiring human-like abilities, such as reading language, recognising images, making decisions or forecasting. Some AI follows rules written entirely in advance, such as a system checking whether a transfer exceeds a limit. But most of the AI we hear about today learns from data.

Machine learning and deep learning

Machine learning (ML) is AI that does not need every rule written out. Instead, the system learns patterns from many examples, such as looking at customers' purchase history to predict who is likely to stop using a service. Everyday examples include product recommendations in shopping apps and spam filters.

Deep learning is a subset of ML that uses neural networks with many layers. It suits complex data like images, audio and language. Almost all the newer AI you use is built on this foundation.

What is generative AI?

Generative AI is AI that creates something new, not just classifies or predicts: writing text, generating images, producing audio or writing code. Everyday examples include drafting emails, summarising reports or making images for posts.

What is an LLM?

An LLM (Large Language Model) is a generative AI model specialised in language. It is trained on huge amounts of text until it learns patterns of language use. The basic principle is predicting the most suitable next piece of text, step by step, repeated until it forms a whole answer. ChatGPT, Claude and Gemini are AI assistants that run on LLMs.

How they relate

AI is the broadest. Inside it is machine learning; inside ML is deep learning; most generative AI is built on deep learning, and an LLM is generative AI focused on language.

Terms you will hear at work

Prompt: the instruction or question you type to the AI. The clearer the context, goal and output format, the better the answer.
Token: a small unit of text the model processes, often used for pricing and text length.
Context window: how much text the model can take in at once, such as how long an attached document can be.
Hallucination: when AI gives wrong information that sounds confident.
RAG: having the AI retrieve information from specified documents before answering, such as the company HR manual, so answers match real data more closely.
Fine-tuning: further training a model on specialised data so it performs certain tasks better.
AI agent: AI that does not just answer but plans and carries out several steps using tools. Read more in What is an AI agent.

Cautions

Always check facts: numbers, names, laws and references from AI may be wrong.
Protect confidential data: do not paste customer or internal data into tools your organisation has not approved.
AI reflects its training data: it may be biased or unaware of recent events.
You still own the work: use AI to draft, but you make the decisions and take responsibility.

You do not need to know how AI is built, but you do need to know what it is good at, where it fails and when to use it.

Where to start: a 4-week learning plan

Week 1: understand the terms in this article and try an AI assistant on a small task, such as summarising an article.
Week 2: practise writing prompts with context, a goal and an output format. Read What is prompt engineering.
Week 3: pick one real task you repeat every week and let AI help draft it. Note whether it saves time or where you need to edit.
Week 4: get to know AI agents and basic automation.

Courses on Plants.work Learn to build your foundation:

Browse more partner courses at Plants.work Learn, and if you want to know how AI skills can grow your career, talk to the AI Career Assistant.