Unlike RAM, secondary storage retains data permanently, even when the computer is switched off.
Hard Disk Drive (HDD): Uses spinning magnetic disks to store data; offers large capacity at a relatively low cost.
Solid State Drive (SSD): Uses flash memory chips with no moving parts, making it significantly faster and more durable than an HDD.
Optical Discs: CDs, DVDs, and Blu-ray discs that store data using laser technology; now largely replaced by online storage.
USB Flash Drives: Small, portable storage devices that connect via a USB port, useful for transferring files between computers.
Cloud Storage: Data stored on remote servers accessed via the internet, allowing files to be reached from any connected device.
3.5 Input Devices
Input devices allow users to enter data and commands into a computer.
- Keyboard: The primary device for typing text and issuing commands.
- Mouse: A pointing device used to interact with graphical elements on screen.
- Touchscreen: Allows direct interaction with the display using fingers or a stylus.
- Scanner: Converts physical documents or images into digital form.
- Microphone: Captures audio input for recording or voice commands.
- Webcam: Captures video input, commonly used for video calls.
3.6 Output Devices
Output devices present processed data to the user in a usable form.
- Monitor: Displays visual output such as text, images, and video.
- Printer: Produces a physical, paper copy of digital documents.
- Speakers: Produce audio output.
- Projector: Displays computer output on a large screen or wall for group viewing.