Operating Systems Flashcards
Choice & use of operating systems
What is an operating system
The platform which enables software installed on a digital device to work. It manages all the resources on the computer. Without it, you PC would be useless
What is Real-time operating systems (RTOS)
A system which process data in current real time.
For example Linux and Windows
What are the advantages of real-time operating systems
- Provides fast response
- Best used where inputs must be processed & responded immediately
such as traffic light systems
What is Single-use single task operating systems
One user can use the system at a time, and one application can run at a time
such as on a basic mobile phone, unlike a smartphone, which runs several software applications at the same time
What are the advantages of single-use single task operating systems
- Requires fewer resources
- Best used on devices that have limited processing and memory, which could not handle running multiple applications
What is Single-use multitasking operating systems
One user can use the system at a time, but many applications can run simultaneously
What are the advantages of single-user multitasking operating systems
- Allows the user to use several applications at once
- Best used on systems where a user needs to be able to switch quickly between applications
For example an office worker using a PC
What is a Multi-user operating system
When many users can use the system at the same time & can run many applications simultaneously.
What are the advantages of a multi user operating systems
- Processing and resources can be shared by multiple users
- Best used were many users need access to the resources at the same time.
Example web users
What are the factors affecting operating system performance
Hardware
Malware
Virtual memory
How is hardware affecting the operating system performance
- Limited RAM capacity
- Limited CPU speed
- Number of cores
- Slow hard disk
How is malware affecting the operating system performance
- Viruses
- Worms
- Spyware
How is virtual memory affecting the operating system performance
- Heavy reliance on virtual memory slows down performance due to slow disk transfers instead of fast RAM data transfers.
- Insufficient HDD space limits RAM extension.
What does networking do in an operating system
Controls access to resources & devices on a network.
Networking operations include tasks such as: managing remote printing, user management & backing up files
What does security do in an operating system
Ongoing checks are conducted on the system & its software to detect attacks. Data from these checks is analysed and collated to generate extensive intelligence about the IT system’s health.
Features to improve security:
- User authentication
- Antivirus & firewall software
- Backup facilities
What does memory management do in an operating system
The operating system manages the computers resources, such as its memory
To do this, the operating system decides & tracks:
- which processes to allocate memory to
- how much memory to allocate o each process
- When to un-allocate memory
- transferring data to the pagefile on the HDD temporarily to the free RAM
What is multitasking in an operating system
Allows you to run more than one application simultaneously. To do this, the operating system must be able to allocate resources (CPU, memory, disk space) to each application in order to allow it to complete two or more tasks simultaneously
What is device drivers in an operating system
The operating system manages your peripheral devices by using a driver to link the digital device with peripherals such as printers
What is a graphical user interface
This is how users interact with a device by controlling a pointer or touch screen to select icons & menus displayed on screen.
GUIs are widely used on devices from PCs to smartphones
What are the pros & cons of a GUI
Pros
- Simple method of interacting is easy for beginners to use
- Doesn’t require users to learn any commands to perform tasks
- Usually options to adapt the interface according to the users needs
e.g. changing the font size
Cons
- Often resource intensive, requiring a lot of processor power & memory
- Experienced users can find it frustrating to complete tasks they could perform CLI with one command
What is a command line interface (CLI)
When the user interacts with the computer by typing in commands in response to prompts displayed on the screen
What are the pros & cons of a CLI
Pros
- Experienced users find it quicker to complete tasks
- Requires far less memory & processing power than GUIs to run
Cons
- Requires knowledge of the specific commands for performing functions
- Learning so many commands can be intimidating for inexperienced users
What is a menu based interface
Users interact using a simple menu that presents options to choose from
An example is an ATM screen
What are the pros & cons of a menu based interface
Pros
- The limited number of options makes it easier to use
- It is often possible to figure out how to perform tasks without any instruction
- They can include options to adapt the interface for an individual users needs e.g. by providing speech output or a choice or larger font size
Cons
- Performing tasks can be slow & frustrating where many levels of options must be traversed
