System Software

Question 1

Why do we need OS?

Answer 1

• They provide an interface between the user and the hardware
• allowing the user to interact with the system and run applications

Question 2

What are main functions of OS?

Answer 2

• Resource management
• File management
• Interrupt handling
• Security
• Providing a platform for software to run
• Providing a user interface
• Providing utilities

Question 3

What is resource management?

Answer 3

OS manages:
- CPU
- memory
- disk drivers
- printers
OS allocates resources to specific tasks and ensures they are used effectively

Question 4

What does the OS do if multiple applications are opened simultaneously? (resource management)

Answer 4

Decides:
- how much memory to allocate to each application
- when and how long each application gets to use the CPU
- how to handle data being read from or written to the hard drive

Question 5

What is file management?

Answer 5

OS handles (of files):
- storage
- retrieval
- manipulation
OS provides a GUI of the file system. User can decide which directory to save file to and file name.

Question 6

What is interrupt handling?

Answer 6

Interrupt events require immediate attention of CPU
Interrupt handled by their priority

Question 7

What is security in the OS?

Answer 7

OS provides:
- Firewall
- Virus scanning
- File encryption
- Password-protected system accounts
System accounts can be restricted from:
- editing network settings
- installing unapproved software
- changing account settings of other users

Question 8

How does the OS provide a platform for applications to run?

Answer 8

OS allows software access to system resources
e.g. game requires intensive graphics —> OS grants it access to GPU

Question 9

How does the OS provide a user interface?

Answer 9

• GUI - visual
• CLI (command-line interface) - text-based

Question 10

What are some examples of utility software?

Answer 10

• Disk defragmentation: better organsises files on the hard disk so that they are stored contiguously- leads to more efficient access and smoother operations
• File encryption: encodes contents of files into a non-readable file - if sensitive data is lost/stolen data protected from misuse
• Backup software: creates system snapshots and will restore them on demand - can return to a point in history where certain data was available
• File compression: reduces file size to consume less hard disk space - files can be transferred faster over a network (e.g. in an email) as use less bandwidth
• Disk cleanup: finds and removes duplicate or corrupted files - frees up disk space