1.1 How Does a Computer Work?Every computer operation can be divided into
three stages: input, process and output.
Input, process and output
1.1 How Does a Computer Work?
A student working on a worksheet
Washing clothes by a washing machine
Example of ‘input process output’
1.1 How Does a Computer Work?‘Input process output’ represents
the three stages of a computer operation process.
InputEnter data andcommand into acomputer.
ProcessThe computerworks on thedata.
The computershows theprocessed results.
Output
Three stages of a computer operation process
1.1 How Does a Computer Work?‘Input process output’ represents
the three stages of a computer operation process.
InputEnter data andcommand into acomputer.
ProcessThe computerworks on thedata.
The computershows theprocessed results.
Output
Three stages of a computer operation process
1.2 What are the Components of a Computer System?• Hardware
– the physical part of a computer system – includes a system unit and a number of
external devices attached to it• Software
– a sequence of instructions– command the computer system to
complete specific tasks
1.2 What are the Components of a Computer System?• Hardware
– composed of input devices, a system unit, output devices
1.2 What are the Components of a Computer System?• Input devices
– for entering commands or data into the computer
A scannerA mouse A keyboard A microphone
1.2 What are the Components of a Computer System?• System unit
– contains a central processing unit (CPU), circuit boards, a power supply and storage devices
– works on data together with the software to produce processed results
System unit
1.2 What are the Components of a Computer System?• Output device
– The processed result can be displayed to users by different output devices.
SpeakersA printerA monitor
• Software– Software can be classified into two types:
system software and application software.
1.2 What are the Components of a Computer System?
• System software– manages the operations of computer
hardware– helps us operate the computer system easily– controls and facilitates the execution of the
application software
Macintosh Operating SystemMicrosoft Windows XP
1.2 What are the Components of a Computer System?
• Application software– carries out specific tasks for the user– application software cannot be run on a
computer system without the presence of an operating system
1.2 What are the Components of a Computer System?
• Relationship between software and hardware
1.2 What are the Components of a Computer System?
1.2 What are the Components of a Computer System?
Type of application software
Function Example
Word processor Create, edit, format, save and print documents.
Microsoft Word
Spreadsheet • Perform calculation and data manipulation.
• Create charts.
Microsoft Excel
Type of application software
Function Example
Presentation software Create presentations and slide shows.
Microsoft PowerPoint
Image editing software Edit photos and graphics.
Ulead Photolmpact
1.2 What are the Components of a Computer System?
Type of application software
Function Example
Communication software
Exchange messages betweendifferent computers.
Microsoft Outlook
1.2 What are the Components of a Computer System?
Type of application software
Function Example
Communication software
Exchange messages betweendifferent computers.
Microsoft Outlook
1.2 What are the Components of a Computer System?