Types of Storage

Overview

• Storage Devices: Read/write data using drives.
  • Media: The physical form where data is stored.

Optical Storage

• Optical Drive and Media Types:
  • CDR (Compact Disc Read Only)
  • CDRW (Compact Disc Read Write)
  • DVDR (Digital Versatile Disc Read Only)
  • DVDRW (Digital Versatile Disc Read Write)
  • Blu-ray (high capacity, replaces DVD)
• Usage:
  • CDRs: Music storage and distribution.
  • CDRWs: Backup storage.
  • DVDs: Movies, high-definition storage.
  • Blu-ray: High-definition movies.
• Mechanism:
  • Uses lasers to read/write data.
  • Read-Only: Pits and lands created by laser burning.
  • Writable: Reversible chemical reactions.
• Pros:
  • Cheap, lightweight, portable.
• Cons:
  • Slow access, prone to scratches.

Magnetic Media

• Hard Disks:
  • Use magnetic disks.
  • High capacity, slower due to moving parts (drive head).
  • Mechanical components eventually fail.
• Tapes:
  • High capacity, slow sequential access.
  • Easy off-site backup, largely outdated.
  • Superseded by portable hard disks and cloud storage.

Solid State Drives (SSD)

• Characteristics:
  • Small, lightweight, fast access, no noise.
  • Different types are emerging, replacing hard disks.
• Mechanism:
  • Uses electricity to move electrons into floating gates.
  • Limited lifespan due to oxide layer deterioration.
• Pros:
  • Reliable, no moving parts, low power, no defragmentation.
• Cons:
  • Limited read-write cycles, expensive.

Recap

• Optical: Low capacity, slow, portable.
• Magnetic: High capacity, quick, but mechanical failures.
• Solid State: Medium capacity, fast, reliable, but limited lifespan.