Operating Systems - computer science Flashcards
1
Q
What is an operating system?
A
An operating system (OS) is software that helps to manage resources of a computer system
2
Q
What is the role of the Operating System?
A
manage the CPU so that applications and processes can be run efficiently
3
Q
Manage Memory (RAM)
A
- The OS reserves memory space in RAM for stored programs to be copied into.
The FDE cycle is executed continuously to carry out the instructions - The OS ensures that programs are appropriately managed so that data is stored in correct memory locations and not corrupted
4
Q
Manage Interrupts
A
- A interrupt is an alert signal sent to the CPU when an application or hardware device requires immediate attention.
- The OS must efficiently manage interrupts so that a problem can be dealt with quickly if one occurs
5
Q
Manage Multi-Tasking
A
- The OS manages tasks so instructions can be executed by the CPU in turn (known as scheduling)
- The OS prevents processes from interfering with others and crashing.
Tasks should appear to run simultaneously even though only one process can be executed at a time
6
Q
Manage Backing Store
A
- T The OS ensures data is stored correctly and can be efficiently retrieved from the backing store.
- Files are organised in a hierarchical (logical) structure
7
Q
What is another name for backing store?
A
Backing store is another name for Secondary storage devices
e.g. magnetic hard disk drive, optical drives or solid state memory sticks
8
Q
Manage Peripherals
A
- A peripheral is an external device connected to a computer system to input or output data
- The OS manages the receiving of data from input devices(e.g. a keyboard or mouse) and the transfer of data to output devices (such as a monitor or speaker)
9
Q
What is a peripheral?
A
- A peripheral is an external device connected to a computer system to input or output data
10
Q
Manage Security
A
- The OS allows users to create, manage and delete accounts with different permissions.
- It also permits multiple users to log in and change passwords
- Antivirus and firewall software is managed by the OS as well as some data encryption processes
11
Q
Manage the User Interface
A
- The OS provides a user interface , allowing a human to interact with the computer system.
- The way in which a user can navigate a computer system is known as a human- computer interaction (HCI)
12
Q
What is the most common type of user interface?
A
Graphical User Interface (GUI)
13
Q
Give ways Graphical User Interfaces can be presented
A
Icons - displayed to represent shortcuts to applications and files
Multiple Windows - can be opened at the same time and switched between
Menus - can be opened from the Start button to display files and shortcuts
Taskbar - allows shortcuts to be pinned for quick access
System settings - can be accessed as network and hardware options
A folder and file system - displayed and manipulated allowing for copying, searching, sorting and deleting data
Customization - the interface can be customised, such as changing font sizes and the desktop background
14
Q
Command-Line interface
A
- Entirely text-based
- Requires users to interact with the system by typing commands
- This is a complicated process and mistakes could easily accidentally delete data.
- There are many commands to learn so only experts who have been trained to learn this interface will be able to efficiently make use of it.
15
Q
What is Touch-Sensitive Interface used for?
A
Smartphones and tablets
16
Q
Touch- Sensitive Interface
A
- A human interacts with the device by pressing on a touch screen making it very intuitive and suitable for most users without training
- Touch-sensitive interfaces may not work with dirty or wet fingers and it will take longer to write text compared to using a keyboard
17
Q
Menu-Driven Interface
A
- displays data in a series of link filled menus. e.g cash machines(ATMs) and old iPods.
- Generally user friendly and easy to use as commands do not need to be memorised
- It can be annoying to find specific data through a large number of menus without a search feature.
18
Q
What is an example of a Menu-Driven interface?
A
Cash Machines(ATMs) and old iPods
19
Q
Voice-Driven Interface
A
- A voice-driven interface can be controlled by speaking commands aloud to a listening device. e.g. Amazon’s Alexa devices , Apple’s Siri technology and Google Home
- This interface is intuitive, can be used hands-free and helps to speed up processes.
- Commands may be misheard or limited in what can be performed
20
Q
Examples of Voice-Driven Interfaces
A
voice-driven interface can be controlled by speaking commands aloud to a listening device. e.g. Amazon’s Alexa devices , Apple’s Siri technology and Google Home
21
Q
What is a utility software?
A
Utility software are dedicated programs used for the maintenance and organisation of a computer system
22
Q
Antivirus software
A
- used to locate and delete viruses on a computer system
- The antivirus scans each file on the computer and compares it against a database of known viruses
- Files with similar features to viruses in the databases are identified and deleted
23
Q
Role of the Firewall
A
- A firewall manages incoming and outgoing network traffic
- Each data packet is processed to check whether it should be given access to the network by examining the source and destination address
- Unexpected data packets will be filtered out and not accepted to the network
24
Q
Explain the process of Disk Defragmentation
A
- As files are edited over time they will become fragmented
- This is when the file splits into parts that are stored in different locations on the hard disk drive.
- Files that are fragmented take longer to load and read because of the distance between the fragments of the file
25
Disk Defragmentation
- As files are edited over time they will become fragmented
- This is when the file splits into parts that are stored in different locations on the hard disk drive.
- Files that are fragmented take longer to load and read because of the distance between the fragments of the file
- Defragmentation software is used to rearrange the file on the hard disk drive so that all parts are together again in order
- Defragmentation improves the speed of accessing data on the hard disk drive
26
Backup software
- System backup copies data onto a separate storage device in case the original information is lost or corrupted.
- Backups should be saved regularly and stored in a different location to the rest of the data. Magnetic tape is a common medium backup
- A typical backup policy is one known as 'grandfather - father- son' which uses three different backups at a time
27
Disk Compression
- compression is the process of decreasing the size of a file
- Disk compression is a utility tool that automatically compresses files when saved so that more data can be stored on the hard disk drive
- When a file is to be opened, the program is automatically decompressed.
- Disk compression increases the amount of space on a hard disk drive but it takes longer to open and close files
28
What is compression?
compression is the process of decreasing the size of a file
29
Disk Checker
- This utility is used to scan a hard drive for any corrupted data
- The corrupted data is deleted to speed up reading from and writing to the hard drive
- More advanced disk checkers are used to scan for bad sectors.
- A bad sector is a permanently damaged section of the hard drive which can no longer be used and must be skipped over
30
What is a 'bad sector' in a hard drive?
A bad sector is a permanently damaged section of the hard drive which can no longer be used and must be skipped over
31
Disk Formatter
- prepares a storage device such as the hard disk drive to be used by removing the current data and creating a file system
- A file system manages how data is stored and accessed
- Other devices like a USB stick may need to be formatted before they can be used for the first time
32
Disk Partition Editor
- Within memory , partitions are segments of data that have been grouped together logically on the hard drive disk
- A disk partition editor allows a user to view and modify these memory partitions. options include : creating , editing and deleting partitions
33
Clipboard Manager
- The clipboard is a temporary storage space for copied data. E.g. a large amount of text can be copied and stored on the clipboard to be pasted into another document, even when the original file has been closed
- The clipboard manager adds more functionality to the clipboard to allow multiple pieces of data to be copied, cut and pasted
34
What is the clipboard a temporary storage space for?
Copied data
35
System Profiles
- A system profiler displays detailed information about the applications on a computer system, as well as data about any attached hardware devices
- Information is provided and updated in real-time about the performance of software and internal components such as the CPU
36
Data Recovery
- Data recovery tools allow deleted, corrupted or otherwise inaccessible data to be returned to a usable state.
- The data loss may have been caused by physical damage to the drive, corrupt memory partitions or accidental deletion
- Most data is not permanently removed when it is deleted so data recovery software can often be used to reaccess files
37
What may data loss have been caused by ? (data recovery)
The data loss may have been caused by physical damage to the drive, corrupt memory partitions or accidental deletion
38
Revision Control
- Revision control software manages previous versions of an application so that if an error occurs, the program can be returned to a previous state
- Also called version control software and can be used to manage and monitor changes made to files overtime
39
- Archiving is the process of storing important data that is not currently required. It must not be deleted but it shouldn't take up valuable storage space either
- An archive compresses multiple files using lossless compression into one folder. This archived folder can be stored on a computer system or transferred to a storage device and won't take up much s[ace
40
What is archiving ?
- Archiving is the process of storing important data that is not currently required. It must not be deleted but it shouldn't take up valuable storage space either
41
Cryptographic Utilities
- A cryptographic utility is used to encrypt data so that it cannot be understood if intercepted. Encryption is commonly for data in transit - being sent between devices
- Cryptographic software can also encrypt data at rest - when stored on a hard disk drive e.g. hackers would be unable to use the data
42
File Manager
- The utility tool provides an interface to the user for accessing , editing and moving files and folders on the system
- Programs will be displayed in a hierarchical (ordered) structure with icons representing the application logo or file type
- Files can be ordered in alphabetical, chronological or other orders and the manager provides an abstracted visualization of where the data is stored.
