Topic 3 Part 3: Data Storage

Understanding Storage Technology

Overview of Computer Memory

• Computer memory is categorized into two types: primary (internal) and secondary (external). Primary memory is directly accessed by the CPU, while secondary memory serves as backup for long-term data storage.

Characteristics of Secondary Memory

• Secondary memory is slower than primary memory but offers permanent data storage. It facilitates data transfer between computers and includes various devices like floppy drives, CDs, and tapes.

Types of Storage Devices

Magnetic Storage Devices

• Magnetic storage includes hard disks and floppy disks. Hard disks are typically installed inside computers, with portable versions available. They consist of rotating platters coated with magnetic material.

Optical Storage Devices

• Optical devices such as CDs, DVDs, and Blu-ray discs use lasers to read/write data. CDs can store up to 700 MB; they come in three types: CD-ROM (read-only), CD-R (recordable once), and CD-RW (rewritable).

DVD Variants

• DVDs have a capacity nearly ten times that of CDs and are faster. They also come in recordable (DVD-R), rewritable (DVD-RW), and other formats.

Blu-ray Discs

• Blu-ray discs utilize blue lasers for reading/writing, allowing them to hold up to 25 GB per layer. They can be dual or triple-layered for increased capacity.

Flash Storage Devices

• Flash storage includes USB flash drives and SD cards, which are popular due to their affordability and reliability. USB drives can store up to 1 TB of data.

Online Data Storage Trends

• Cloud storage is gaining popularity as it allows access from multiple devices. This method involves storing data on remote servers rather than local hardware.

Durability vs Capacity in Storage Technology

• The discussion touches on how different technologies compare in terms of durability and capacity, highlighting the importance of these factors in choosing a storage solution.