FOUR Flashcards
(22 cards)
hardware
the physical components of a computer that you can touch
software
the programs that run on the computer
system software
the software that manages the computer’s resources and provides a platform for the application software to run on
application software
the software that performs specific end-user tasks
functions of the OS
file management
provides user interface
memory and processor management
i/o device management
device driver management
application and security management
management of the:
processors
memory
input output devices
applications
security
processor management
OS is responsible for deciding which program will run on the processor and how much time it will get to run
memory management
OS copies program from storage into main memory
OS keeps record of where each program and its data are located
OS makes sure not to overwrite existing data and programs
input/output devices
Operating system usesdevice driversto communicate with i/o devices
application management
provides a platform for applications to run on
manages sytem resources to allow computers to run multiple applications at once—multitasking
provides a user interface (CLI, GUI (WIMP), NLI, menu)
Security management
OS will do
security updates (automatic)
encryption of hard drives and removable media
access rights to files programs and services
memory protection—prevention of programs being able to view or overwrite other programs data stored in RAM
user management—usernames and passwords
utility software
utility programs are used to maintain a computer
defragmentation
data compresssion
anti virus software
disk defragmentation
fragmented—drive head will need to move to more locations, so it is slower to access files and programs
defragmenting—read times are faster and free space is also in one place so new files don’t need to be fragmented
data compression
reduces the amount of storage space needed on a disk
if sending the files, it reduces the amount of data that is sent
compression may allow attachments to be sent via email that may have been to large to send before
more data stored on backup media
low level languages
processor specific
allows the programmer to precisely control any instruction on the processor
program runs very quickly
code will usually require less RAM
assembly code, machine code
high level languages
easier to understand and learn
programs can be written faster
it is easier to understand and debug
have complex date structures: arrays and records
must be translated into machine code
bus
a collection wires through which data/signals are transmitted through one component to another
fetch-execute
f: next instruction is fetched to the CPU from the main memory
d: the instruction is decoded to work out what it is
e: instruction is executed, e.g. reading/writing from/to the maim memory
secondary storage
the non volatile storage that isn’t directly accessible by the CPU
needed to store data and software in the long term
has high capactiy so you can store a lot of data
computers need permanent data storage, so all the software and data are not loast when the computer is switched off
ssd
data is recorded onto solid state memory chips without any moving parts
highly durable, no moving parts
no noisy fan/drive arm
faster start up times
more expensive then magnetic but only has around same storage
optical (e.g. CDs)
laser uses light to read/write data
cheap
portable
takes up little space physically
less storage capacity
not durable, easily scatched
slow write speed
magnetic (hdd)
magnetic parts move over disk to read and write or a drive head reads a magnetic tape
cheap
large storage capacity
relatively fast write speed
many mechnical parts
not durable
not portable
cloud storage
store files via the internet on a remote server owned by a third party
uses magnetic or solid state storage
access from any connected device
files can be shared with others
easy to increase more storage
no need to buy expensive hardware
cloud host provides securtiy and backups for you
need connection to the internet to access files
upload/downlard speeds are slower
dependent on host for security and backups
stored data can be vulnerable to hackers
can be expensive in long term
