Computer Storage Devices

Study Notes

Data must be saved as a file to preserve its contents after the computer is switched off.
Examples of storage devices:
- Hard disk: fixed inside the computer, stores large volumes of data, and can be accessed and retrieved quickly.
- Floppy disk drive: uses removable disks (floppies), can transfer small files between PCs (up to 1.4 MB).
- ZIP/JAZ drives: special disks that can hold more data than floppy disks (up to 100 times more).

CD-ROM drive: reads data from CDs (up to 800 MB), suitable for multimedia applications.
DVD-ROM drive: stores up to 17 GB of data, designed for video and multimedia applications.
CD-R, CD-RW, DVD-R, and DVD-RW drives: allow writing and rewriting data on CDs and DVDs.

A modem and Internet Service Provider (ISP) are required to access the Internet from home.
Search engines (e.g., Google, Yahoo) help find information on the Internet.
E-commerce (online business) is safe, as credit details are encrypted when transmitted over the Internet.
Email is a quick way to send and receive messages, with attachments (e.g., files, photos).

Types of viruses:
- File virus: resides in memory and activates when a specific program is run.
- Boot sector virus: infects the boot sector of a diskette or hard drive, gaining control of the system.
Viruses can spread through:
- Internet downloads
- Pirated software
- Exchange of diskettes
- Email attachments
- Infected documents
Protection against viruses:
- Anti-virus software scans files for virus signatures and updates regularly.
- Cleaning or disinfecting infected files.

Desktop: the screen background with windows, icons, and taskbar.
Icon: a small graphical symbol representing a program, file, or function.
Window: a rectangular area for working on an application.
Taskbar: displays open applications, start button, and allows minimizing and closing windows.
Cursor (mouse pointer): used to select commands or icons, controlled by mouse or keyboard.

Mouse actions:
- Click: quickly press and release the left button.
- Double-click: click the left button quickly twice.
- Drag: press and hold the left button, then move the cursor.
- Drag and drop: drag an object to a new position, then release to drop.
Renaming a file or folder: right-click, select Rename, type a new name, and press Enter.
Cut, Copy, and Paste commands:
- Cut: move information to a new location.
- Copy: create an identical copy, keeping the original intact.
- Paste: place the information in the new location.

Delete information only when it's unnecessary or for confidentiality purposes.
Confirm the deletion is necessary and the information won't be needed in the future.