Refers to the programs we run on our computer - the programs
are the stored sets of instructions given to the processor to carry
out. It also refers to the data that is used by the proograms
Types
Utility Software
Has limited functionality and is
used to maintain computer systems
Application Software
Handles real-world jobs
that users want to do
System Software
Operating System
Functions
Memory
Management
The OS manages the transfer
of data between the CPU,
RAM and main storage
User Interface
The OS provides the user with a way of
controlling the functions of the computer
without resorting to machine code
Command line interface (CLI) e.g. MSDOS.
Commands can be grouped into shell
scripts to carry out maintenance jobs
Graphical (GUI) e.g.
Windows. Uses icons
to represent actions.
No commands have
to be learned.
Acts as a boundary between human and machine
The interface lets users give commands,
ask questions and display a response
Peripheral Management
The OS manages the input and output
devices connected to the computer,
like a keyboard, mouse and printer
Multi-tasking
The OS allows more than one
program to be run at once so users
can switch between applications easily
Security
The OS provides security
features to restrict access to
the system or particular files
Controls hardware and acts
an an intermediary between
application and hardware
(hides complexities and allows
user to operate computer
without writing programs
Utility Programs
Security
Anti-virus
Detects and protects the computer against
virus threats and quarantines infected files
Firewall
Restrict communication in and out of the
computer from the applications that are running
Spyware protection
Detects and removes spyware
(small programs that quietly
monitor what you are doing)
Disk Operations
Formatting
Sets up a hard drive, memory stick or
card into a format that the computer can
use to store/retrieve data. the process of
formatting erases any data that was
previously on the storage medium
File transfer
Allows movement of
files from one location
to another, either locally
or via memory stick
Defragmentation
Re-organises the data on the hard
drive to improve read/write access time
System Maintenance
System info and diagnosis
Provides information about the system in
order to help with diagnosis of problem
System cleanup tools
Removes temporary files and
compresses/archives unused
files to increase free storage
Automatic updating
Uses the Internet to check the OS
is up-to-date and applies software
patches/fixes as necessary
Software
Procurement
Proprietary
Written by developers and allowed to be
used by others but with restrictions e.g. can't
adapt software (source code is hidden)
Extensively tested, updates are scheduled
regularly, reliable, someone to go to if problem
Source code cannot be inspected so may contain
spyware within the software, expensive, inflexible,
deliberate incompatibilities to lock users in
Off the shelf
Developed by a software company
to be sold to the general public
Cheaper than developing it yourself, tech support
available, extensively tested, ready, forums online
Inflexible so customisation (not
exact needs), search for traning
Open Source
Written by general public for everyone to use.
Source code provided so software can be tweaked
Allows anyone to use/adopt the software to meet their
needs and a collaborative approach to development
can lead to better quality software, and cheap
By making source code available to all, provides opportunity
for people to take advantage of software installed on users'
computers compromising security, no or irregular updates,
Custom Written
Developed specifically for a particular organisation.
Specially commissioned for a particular customer.
Meets exact purposes, doesn't require adaptations,
the developer can train, be contacted, and maintain
Expensive, needs technical expertise to develop,
not extensively tested, time-consuming