software Flashcards
system software
software designed to run and maintain a computer system
application software
software that performs specific tasks for the end user
what are the 6 main functions of the operating system
- communication with I/O devices via device drivers
- application management
- control memory management and allocation
- organise CPU and its processing tasks
- deals with file and disk management
- manage system security and user accounts
how does the OS communicate with I/O devices via device drivers
I/O devices allow computers to take inputs and give outputs
every I/O needs a device driver
drivers acts as translators for the signals between the OD and device
once booted up, the OS chooses the right device drivers for the detected device (if new, new drivers may automatically be installed to match it)
device manufacturers could release driver updates to fix bugs, add new features of improve device performance
how does the OS manage applications
OSs provide a platform for applications to run on and manage resources so that multiple applications can run simultaneously (multitasking)
this allows applications to access hardware and peripheral devices as needed
OS provides a user interface that applications are accessed through
applications are generally written for a particular OS and will take advantage of its features
how does the OS manage memory
when an application is opened/launched, tje necessary parts are copied by the OS to memory as well as additional parts as required
if apps or features have not been used recently, the OS may remove these parts from memory
the OS controls how much RAM a program has access to
if multitasking, the OS makes sure that they don’t overwrite or interfere with each other by allocating certain applications certain memory addresses, keeping their processes in separate locations
how does the OS manage CPU processors
once an application has launched, it creates 1 or more processes , each of which has instructions that it needs the CPU to execute
the CPU can only carry out one instruction at a time though, so OS deals with this by scheduling to determine the most efficient order for the CPU to execute instructions
the OS can interrupt the CPU is a higher priority process becomes available
in order to allow multitasking, the CPU switches between different processes very rapidly
how does the OS manage system security
OSs have ways of keeping stored data safe
user account control - allows different users to be granted or denied access to specific data or resources on a computer system
each user has access to their own personal data and the desktop but can’t access another user’s data unless they are a system administrator
some OSs have antitheft measures to prevent users from accessing locked devices or accounts to steal info (this could be through password protection, biometrics or drawing specific patterns)
utility (system) software
any software used to maintain or configure a computer
what are 7 types of utility software
defragmentation disk health compression encryption backup virus scanners system clean up
what is defragmentation utility software
ideally files are stored together on a hard disk, but as files are moved or deleted, gaps are made
new files have to be split up to fill the gaps but this makes files slower to read, as the read/write head has to move back and forth
defragmentation puts the files back into one block and collects all of the free space together
what is disk health utility software
disk health utilities scan the drive for problems and fix issues where possible
what is compression utility software
reduces the size of files so that they take up less disk space
used on Internet to make files quicker to download
compressed files must be extracted before use
what is encryption utility software
scrambles data to stop 3rd parties from accessing it
encrypted data can be decrypted with a ‘key’
what does backup utility software do
a copy of the computer system’s files and settings stored externally that can be restored in the event of data loss, which can occur due to fire, flood, theft, malware, hardware failure etc.
back up utility can schedule regular backups, create rescue disks, disk images, create options for how much data to back up
