1.5: SYSTEMS SOFTWARE PWH fin Flashcards
what is an operating system?
a group of programs that is essential for managing the computer’s resources
what are the 5 major functions of the OS?
user interface
memory management/multitasking
peripheral management and drivers
file management
user management
what does the user interface do?
a means of interacting with the computer
> keyboards, buttons, mice
an interface may be:
-purely text (command line interface),
-menu driven
-graphical user interface (GUI)
-windows, icons, menus, pointer
(WIMP)
what do the peripheral management and driver do?
peripheral devices are connected externally to the CPU
>printers, keyboards, monitors
users communicate with these devices via the OS
a buffer is used to compensate the difference in speed between the CPU and the device
what does the file management do?
the OS allows user to create, delete, move, save and copy files
it can also search for files and free up space for them
this may also manage access rights to individual files
what does user management do?
each user is provided with an account
each user can also be given different levels of access based on their needs and levels of security
the OS can also monitor login activity and logout users after a certain time of inactivity
what are utility programs?
small programs used in conjunction with the OS to manage extra functions
they aren’t essential to running a computer but make specific tasks easier
HOUSEKEEPING
what are 3 examples of utility programs?
defragmentation software
encryption software
data compression software
what is defragmentation software?
files are stored on the hard disk
as files are moved/ deleted, gaps appear
the next file will fill the hole, but if the file is larger than the hole, it will become fragmented (part is cut off)
when you are searching for a file, something fragmented 3 times would take 3 times as long to find
therefore, defragmentation software is used to match the files back up which speeds up the file retrieval and storage times
what is encryption software?
encryption utilities are used to encrypt or decrypt files or folders which are held on a computer, transmitted across a network or transferred to an external device (like a USB stick)
the encryption process uses an algorithm and a key to turn plaintext into cipher text
the algorithm and the key are both needed to decrypt this
what is data compression software?
uses an algorithm to resave the data in an existing file using less space than the original
sometimes data is lost (lossy) and sometimes it can be reconstructive without any loss of information (lossless)
