What are secondary storage devices with its type?

Secondary Memory refers to non-volatile storage that is used to store data and programs permanently, even when the computer is powered off. Unlike Primary Memory, which is volatile and has limited storage, secondary memory offers a larger capacity at a lower cost. It is also referred to as auxiliary memory or external storage, and it is not directly accessible by the CPU but through input/output channels.

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Key Features of Secondary Memory:

1. Non-Volatile: Retains data without power.
2. Large Storage Capacity: Supports storage of vast amounts of data.
3. Cost-Effective: Cheaper than primary memory.
4. Not Directly Accessible by CPU: Requires external controllers or I/O operations.

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Uses of Secondary Memory:

1. Permanent Data Storage: Retains data and programs for long-term use.
2. Large Data Management: Stores high volumes of multimedia, documents, and software.
3. Portability: Some devices, like USB drives and SD cards, can be easily carried and connected to different systems.

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Types of Secondary Memory:

1. Fixed Storage:

• Definition: Built into the computer, not easily removable.
• Examples:
  • Hard Disk Drives (HDD): Magnetic storage offering capacities from GBs to several TBs.
  • Solid-State Drives (SSD): Faster, energy-efficient, and more reliable than HDDs.
  • Internal Flash Memory: Rarely used, non-removable flash memory.

2. Removable Storage:

• Definition: External media that can be detached and used across systems.
• Examples:
• Optical Discs: CDs, DVDs, Blu-ray discs for multimedia and data storage.
• Flash Drives (USB Drives): Compact and widely used for file transfers.
• SD Cards: Small, portable memory cards used in cameras, phones, etc.
• Magnetic Tapes: Used for archival storage in large systems.
• Paper Storage: Historical media like punched cards, now obsolete.

Advantages of Secondary Memory:

1. Durable Storage: Data remains intact even when the computer is off.
2. Cost-Effective Storage Expansion: Offers more storage at a fraction of the cost of primary memory.
3. Portability: Devices like USB drives and SD cards allow easy data transfer.
4. High Capacity: Supports storage of large volumes of data.

Secondary memory plays a critical role in modern computing, enabling long-term data storage and accessibility.