1.5 Systems Software Flashcards
What does the user interface allow
The user to interact with the hardware
Name the four types of user interface
Command line interface
Graphical user interface
Natural language interface
Menu driven interface
What are the features of a command line interface
Difficult to use but powerful and requires less processing power
What are the features of a graphical user interface
Uses windows, icons, menus and pointers
It is easy to use and intuitive
What are the features of the natural language interface
User voice to interact
Very intuitive but limited
What are the features of the menu driven interface
A series of limited menus are shown to the user
What is memory management
organising a computers memory so that is can run multiple programs at the same time and it can multi task
What is time slicing
When each program is given a slice of time to run in the cpu making it feel like they are running at the same time
How does the os maximise the use of space in the memory
It splits the data efficiently in memory by fragmenting them
What is fragmentation
Splitting a program or files into pages so that it can be placed in free spaces in memory/secondary storage
What is a peripheral
A piece of hardware attached to the device
Why does the os use device driver software
To communicate with internal hardware or peripherals connected to the computer
Why does the os use the device driver
To translate the instructions so that the hardware understands the task
What is user management
managing a users digital identity (access to resources and account information)
What users does the os have
Multi user and single user
What is a multi user os
It allows multiple accounts on one device and each account may have different access levels (they can see different files)
What is the features of a multi user os
Each account might have different access levels(see different files), have their own files, programs, settings and desktop and other users cannot see the other users files, programs and settings
What is file management
The organisation of the data into a manageable hierarchal structure by the OS
What does file management allow
The user to create, rename, move and delete folders
What does the os do with the hard drive
writes and reads data to the hard drive
What is stored on the hard drive
Data
What does file extension do
Lets the os know what applications they need to use to open the file
What are examples of file extensions
JPEG - image
MPEG - videos
DOCX - document
Xls - spreadsheet
What does the utility software do
Maintains the computer and useful utilities are installed with the operating system
What does extra utility software do
Perform additional tasks
What does encryption software do
Scrambles data to stop third parties from being able to read and understand it so if data is intercepted when being sent across a network the hacker won’t be able to understand it
What is needed to decrypt data
A private key
What is needed to encrypt data
A public key
Name the two types of keys and what they do
Public key - encrypts data
Private key - decrypts data
Where are files stored
On the hard disk in available space
Why do small gaps in storage appear
Files are created, deleted and moved
Why does the os fragment files
To make them fit in the small gaps
What is the problem with fragmented files
It makes reading and writing slower
What is defragmentation
When the os reorganises the files and putes them back together creating lots of free space together rather than separated
What does defragmenting a SSD do
It reduces its lifespan because it has no moving parts so if it’s fragmented it doesn’t take longer time to read and write to
What is data compression
When the file is compressed to reduce the size of a file
What does data compression allow
More files to be stored and for them to be downloaded faster
What is lossy compression
Permanently deletes data that won’t be noticed but the file cannot be restored to its original quality
What is lossy compression used on
Images (jpeg)
Advantages of lossy compression
It significantly reduces the file size
Disadvantages of lossy compression
It can be worse quality
What is lossless compression
Uses an algorithm to compress a file and the file can be restored to its original quality when uncompressed
What is lossless compression used for
.zip (zipped files)
Advantages of lossless compression
Better quality
Disadvantages of lossless compression
Doesn’t reduce the file size as much
