Operating Systems Flashcards
What are the functions of an OS? (Operating System)
Communicate with external and internal hardware
Provide a UI so that the user can interact with the computer and vice versa
Provide a a platform for different applications to run
Allow the computer to multi-tas kby controlling memory resources and the CPU
Deal with file management and disk management
What does a device driver do?
They allow the OS and the hardware to communicate to each other
How is drivers incorporated into the OS?
When the PC boots the OS detects the hardware, then it will run the driver, if it detects new hardware or an update to the driver it will install the new drivers
What types of UI are there, who uses them?
A GUI is a graphical user interface that some OS offer, that allow the user to click on icons and specific input methods to control the OS (like windows or iOS) and they are typically used for light users and the everyday use
There is also command line which gives you far more control over the OS and is less resource heavy, they are more efficient for advanced users and are more powerful.
How can an OS multitask?
When an application is opened the OS moves all data needed to the memory
To run multiple applications the OS must decide make sure that the two applications running data doesn’t interfere with each other
Only one application can be run by the CPU at a time, the OS must divide the time spent by the CPU and will prioitise certain processes into an efficient order
The OS will manage the data to and from virtual memory
How does the OS manage files and the HDD?
Organises data into a hierarchical system
Splits the disk into sectors and sees how much data is left on the system
Uses utility software (defragementation) to maintain the hard disk
Also deals with any users logged onto PC by writing data to their allocated space
How does the OS manage different users?
the OS can restrict data access to other peoples personal data
Only some users that have been designated by the admin of that PC can write or install new programs onto the HDD
Also protects users accounts by having passwords and fingerprint an retina scanners that can identify the user
What is utility system software?
It is software that helps maintain or configure a computer
What does a de-fragmentation software do?
It puts broken up files back together again, which speeds up read and write times.
How does a HDD become fragmented?
Files are stored onto available spaces on the HDD
Over time as files are deleted and moved and change size lots of small gaps appear.
The OS splits the files into smaller parts to fill up the gaps made
So the read and write speeds become slower as the head has to move back and forth across the HDD
Can and SSD become fragmented?
NO
It uses flash storage with no moving parts, they can access data just as fast as a result
How does de-fragmentation software work?
De-fragmentation software reorganises data on the hard disk drive to put fragmented files back together. It moves files to collect all the free spaces together. This helps prevent further de-fragmentation.
What is a backup utility software?
It schedules regular backups, creates rescue disks, disk images, and options for either full or incremental back ups
What is a back-up?
it is a copy of a computers system files ans settings stored externally, which means data can be recovered if there is a case of data loss
What is a full back up?
It is where a copy is taken of every file on the system. They often use a lot of storage space. A full backup can take a long time to create, but is faster to restore from
What is an incremental back-up?
they are where only the files created or edited since the back up was last copied. They use less storage space and are much quicker to create. But a full system restore is slow-the last full system backup must be restored, followed by every incremental backup since that point.
What is compression software?
Compression software reduces the size of the files so that they take up less disk space. Its used loads on the Internet to make files quicker to download. Standard file formats are .zip and .rar. They need to be extracted before they are used
What is encryption software?
Scrambles data to stop third parties from accessing it, it can only be de scrambled with a special ‘key’
What is open source software?
It is software where the source code is made freely available and users may legally modify the source code to create they own spin off software which can be shared with the same license and terms as the original software
Give some examples of open source code?
GIMP VLC media player Apache HTTP server Linux Android UBUNTU
What can people do who use the open source code do to the developers?
Suggest bug fixes and improvements to the software and mention any security issues or weaknesses
What are the advantages of using open-source software?
Its free usually
Made for the greater good and not profit
Can be adapted by users to suit their needs
People can collaborate to bring patches to the code
Popular open source is very secure and reliable as it is often patched by the community
What are the disadvantages of using open-source software?
Small projects may not get regular updates, so may be buggy and may have security issues
There may be limited user documentation
No warranties if something goes wrong
No customer support if something goes wrong(but user community is usually good at fixing issues on forums)
Companies using open-source software may not want competitors to see their source code but the have no choice
What is proprietary software?
Is where only the compiled code is released, the code is usually a close guarded secret
What does a proprietary software licence mean?
It means that modifying, copying and redistribution of the software is restricted (usually paid for)
State some examples of proprietary software
Microsoft Windows
Office
Adobe
Computer Games
Why do businesses tend to use proprietary software instead of open source software?
They have better customer support options and tend to be better coded as it is sold as a product
What are the advantages of proprietary software?
Comes with warranties, documentation and customer support
Should be well-tested and reliable as the companies reputation depends on the fixes and updates will come regularly
Usually cheaper for companies than developing their own custom-built software
What are the disadvantages of proprietary software?
Can be expensive
software may not exactly fit a users needs and they can’t do anything about it
software companies may not maintain older software after warranties expire - they’ll want people to buy their latest product
