💾 COMPUTER STORAGE DEVICES – Complete Notes
(Home Academy | Exam-Oriented for JKSSB, SSC, Bank, UGC NET)
1. Meaning of Storage Devices
Storage devices are hardware devices used to store data and information permanently or temporarily for future use. They hold data, programs, and files, allowing the computer to access them when needed.
2. Types of Storage Devices
2.1 Primary Storage (Main Memory)
Primary storage is volatile memory that loses data when power is off. It stores data temporarily while processing. Examples include RAM (Random Access Memory) and Cache Memory, which is high-speed memory located inside the CPU for faster processing.
2.2 Secondary Storage (Auxiliary Storage)
Secondary storage is non-volatile memory that retains data even when power is off. It stores data permanently for long-term use. Examples include Hard Disk Drive (HDD), Solid State Drive (SSD), Pen Drive / USB Flash Drive, and Optical Discs (CD, DVD, Blu-ray).
2.3 Tertiary Storage (Offline Storage)
Tertiary storage is used for backup, archiving, and rarely accessed data. It is often used in data centers or organizations. Examples include magnetic tapes and optical jukeboxes.
2.4 Cloud Storage
Cloud storage stores data remotely on servers accessed via the internet. Examples include Google Drive, OneDrive, Dropbox, and iCloud. It allows access from anywhere, provides secure backup, and requires no physical device.
3. Characteristics of Storage Devices
Capacity refers to the amount of data a device can store, measured in GB or TB. Speed refers to the time taken to read or write data. Volatility indicates whether data is retained after power off, as in volatile or non-volatile memory. Portability shows the ability to move data from one computer to another. Cost refers to the price per unit of storage.
4. Difference Between Primary and Secondary Storage
Primary storage is volatile and used as temporary working memory. Secondary storage is non-volatile and used for permanent storage. Primary storage includes RAM and Cache Memory, is very fast, and expensive per GB. Secondary storage includes HDD, SSD, and Pen Drive, is slower, and cheaper per GB.
5. Important Notes for Exams
RAM is temporary memory that loses data on power off. ROM is read-only memory storing permanent instructions. HDD is magnetic storage with high capacity but slower speed. SSD is faster, more durable, and has no moving parts. Tertiary storage is used for backup and archives. Cloud storage is internet-based and accessible anytime.
📘 MCQs – Storage Devices
Which of the following is volatile memory? A) RAM B) HDD C) SSD D) Pen Drive
Answer: A) RAMWhich of the following is permanent storage? A) RAM B) Cache C) ROM D) CPU Registers
Answer: C) ROMSSD stands for: A) Standard Storage Device B) Solid State Drive C) Secure Storage Disk D) Simple Storage Device
Answer: B) Solid State DriveWhich storage device is portable and uses flash memory? A) Hard Disk B) Pen Drive C) RAM D) Cache
Answer: B) Pen DriveTertiary storage is mainly used for: A) Daily processing B) Backup and archives C) High-speed memory D) Temporary data
Answer: B) Backup and archivesWhich of the following is a cloud storage service? A) SSD B) Google Drive C) DVD D) HDD
Answer: B) Google DriveMain difference between primary and secondary storage is: A) Speed and volatility B) Color and size C) Brand and cost D) Input/output capability
Answer: A) Speed and volatilityMagnetic tape is an example of: A) Primary Storage B) Secondary Storage C) Tertiary Storage D) Cache Memory
Answer: C) Tertiary StorageROM is mainly used to: A) Store operating system instructions permanently B) Temporary memory storage C) Increase CPU speed D) Store video games
Answer: A) Store operating system instructions permanentlyCache memory is located: A) Inside CPU B) On HDD C) On SSD D) On Pen Drive
Answer: A) Inside CPU