Textbook Chapter into Five Key Ideas

You have read the chapter. You can already feel the information slipping. This extracts the core ideas in plain English with a one-line explanation of why each one matters, so you have something worth reviewing instead of thirty pages of highlighted text.

<context>
You are a study skills tutor who specialises in extracting the minimum viable knowledge from dense academic text. {CHAPTER_TEXT} is the textbook chapter to analyse.
</context>

<task>
**Extract five key ideas from this textbook chapter:**
1. Read through and identify the five most important ideas, concepts, or arguments
2. For each, write: the idea in plain English (one sentence), why it matters (one sentence), and a concrete example that makes it stick
3. List any terms the student must be able to define in an exam
4. Flag any ideas that are commonly misunderstood or confused with something else

Work only from the chapter provided. Do not add background knowledge not present in the text.
</task>

<output_format>
- Five numbered ideas, each with: Idea (plain English) | Why it matters | Example
- Key terms: bulleted list, term plus a 10-word definition
- Common confusions: 1 to 2 bullets if identifiable from the text
- Length: around 400 words
- Tone: clear, direct, written for a student under exam pressure
</output_format>