Removable media drives

•  A DVD/CD reader/writer drive is nearly universal on full-sized models, and is common on thin-and-light models; it is uncommon on subnotebooks and unknown on netbooks. CD drives are becoming rare, while Blu-Ray is becoming more common on notebooks.^[39]
• Internal storage: Laptop hard disks are physically smaller—2.5 inches (64 mm) or 1.8 inches (46 mm) —compared to desktop 3.5 inches (89 mm) drives. Some newer laptops (usually ultraportables) employ more expensive, but faster, lighter and power-efficient flash memory-based SSDs instead. Currently, 250 to 500 GB sizes are common for laptop hard disks (64 to 512 GB for SSDs)