Lesson Plan

• Describe the physical structure and principle of operation of optical discs.
• Compare the capacities, laser wavelengths, and typical uses of CD, DVD, and Blu‑ray.
• Identify proper handling, storage, and care procedures to maintain disc integrity.
• Evaluate the advantages and disadvantages of optical discs relative to other storage media.

• Projector or interactive whiteboard
• Computer with optical drive (CD/DVD/Blu‑ray)
• Sample optical discs (CD, DVD, Blu‑ray)
• Printed handout or worksheet with comparison table
• Diagram of disc cross‑section
• Soft lint‑free cleaning cloth

Begin with a quick poll: Who has used a CD, DVD or Blu‑ray recently? Briefly recap previous lessons on storage media, highlighting magnetic vs optical technologies. Explain that today’s success criteria are to describe how optical discs work, compare their specifications, and demonstrate correct handling.

1. Do‑now (5'): Students list storage media they have at home on sticky notes.
2. Mini‑lecture (10'): Explain optical disc structure and laser reading principle using a diagram.
3. Guided comparison (12'): Present CD, DVD, Blu‑ray specifications; students complete a comparison chart on the worksheet.
4. Hands‑on handling demo (8'): Demonstrate proper disc handling, cleaning, and storage; learners practice with sample discs.
5. Check for understanding (5'): Quick quiz/exit ticket covering key differences and care procedures.

Summarise that optical discs differ mainly in capacity, laser wavelength and typical applications, and that careful handling extends their lifespan. For the exit ticket, ask learners to write one advantage and one disadvantage of each disc type. Assign homework to research a modern use case for Blu‑ray or an alternative high‑capacity storage medium.