Unit A451:
Computer systems and programming
Section 3: Software
1 – Intro to software
Section Objectives
Candidates should be able to:
(a) Explain what is meant by the term ‘software’
(b) Be aware of what an operating system is and be aware of
different examples of operating systems
(c) Understand the difference between ‘command line
interfaces’, ‘graphic user interfaces’ and ‘menu driven
interfaces’
What is software
•What do you understand the meaning of the
term ‘software’ to be?
SOFTWARE AND OPERATING SYSTEMS
What is software
•WHAT IS SOFTWARE?
•Software is the why we use a computer. These
are the programs that allow us to do something
useful with our computer.
•Without software to make them work,
computer systems are just electronic circuits
without instructions telling them what to do.
SOFTWARE AND OPERATING SYSTEMS
Operating Systems
What is meant by the term ‘operating system’
SOFTWARE AND OPERATING SYSTEMS
What is an Operating System?
•WHAT IS AN OPERATING SYSTEM?
•Most modern computer systems, from laptops
to phones to games consoles, need to have
some software that makes the hardware work
properly.
•This is called an Operating System (OS).
SOFTWARE AND OPERATING SYSTEMS
Operating Systems
Can you think of any examples of Operating
systems?
SOFTWARE AND OPERATING SYSTEMS
Operating Systems
SOFTWARE AND OPERATING SYSTEMS
Types of software interface
Operating systems allow the user to interact
with different software packages on a
computer.
The way they do this is by providing an
interface.
SOFTWARE AND OPERATING SYSTEMS
Types of software interface
There are three main interfaces that can be
used to interact with operating systems.
Graphic User Interface
Menu Driven Interface
Command Line Interface
SOFTWARE AND OPERATING SYSTEMS
Command Line
• Command line interfaces are best used by
experts!
• In the early days of personal computers, all
PCs used command-line interfaces.
• They are used by typing in commands to
interact with software and perform tasks
• An example of a common command driven
interface is MS-DOS. The MS-DOS command
to display all files on c:\ would be: dir c:\
SOFTWARE AND OPERATING SYSTEMS
Command Line
• Commands must be typed correctly and in the right
order or the command will not work. This can be
tricky for beginners.
• Experienced users who know the commands can
work very quickly without having to find their way
around menus.
• An advantage of command driven programs is that
they do not need the memory and processing
power of the latest computer and will often run on
lower spec machines.
SOFTWARE AND OPERATING SYSTEMS
Command Line
SOFTWARE AND OPERATING SYSTEMS
Menu Driven Interface
• A menu driven interface is one that the user
needs to use set menu items to navigate
through
• A menu of options is offered to the user and
they can chose from the options set by the
designer of the system.
• Like a menu system on a Sky TV or a Virgin
Media box.
SOFTWARE AND OPERATING SYSTEMS
Menu Driven Interface
• They are easy to use as the user does not
have to remember sets of commands.
• They are user friendly - you can often guess
your way around the options.
• They can be irritating if there are too many
levels of menus to move around - with a
command-line interface you can go to the
option required immediately.
SOFTWARE AND OPERATING SYSTEMS
Menu Driven Interface
SOFTWARE AND OPERATING SYSTEMS
Graphic User Interface
• Graphical user interface is sometimes
shortened to GUI. The user chooses an
option usually by pointing a mouse at an icon
representing that option.
SOFTWARE AND OPERATING SYSTEMS
Graphic User Interface
• They are much easier to use for beginners.
• They enable you to easily exchange
information between software using cut and
paste or 'drag and drop'.
• They use a lot of memory and processing
power. It can be slower to use than a
command-line interface if you are an expert
user.
SOFTWARE AND OPERATING SYSTEMS
Graphic User Interface
SOFTWARE AND OPERATING SYSTEMS