A computer is an electronic machine that can process data, store information, and produce output. It consists of both hardware and software. The hardware includes the system unit, monitor, keyboard, and other peripherals. The software includes operating systems and application programs. When a computer is powered on, it goes through the booting process to start up. Users can then log in, navigate the desktop interface, open programs and files, and perform tasks. Computers come in different types but most common are digital computers that use binary digits for calculations.

1. BASIC COMPUTER
COMPUTER BASICS FOR PUBLIC HEALTH [WEEK ONE(1)]

2. WHAT IS A COMPUTER?
• A computer is a special machine that is capable of processing data very
quickly and produced the new information called output.
• A computer is an electronics machine that can accept input process,
stores and give output called information.

3. KEYWORDS IN THE PROPER DEFINITION OF A COMPUTER
• INPUT: This is the method of getting instruction and data into the system through the input devices like,
the keyboard, mouse, monitor, scanner, flash drive etc.
• OUTPUT: This is the method of getting the outgoing information through output devices like the VDU,
Printer, speaker etc.
• DATA: This is the raw material or the unprocessed form of the information. The computer receives
human information as data because there is a language barrier between the computer and man. Therefore
the interpreter between man and computer is the operating system which converts human language to
machine language and machine to human language Vice Versa.
• PROCESS: Because there is language barrier between man and the system, the computer has a very
sensible chip called the CENTRAL PROCESSING UNIT (CPU), this unit is responsible for
processing of Data with the help of the operating system. It is known as the brain of the computer.
• STORAGE: The storage of the processed data known as information is done by the main memoires of
the computer via the CPU, which are the RAM and ROM in the primary storage unit and the disks
(Hard disk, floppy disk, Com pact disk, magnetic tape etc.) in the secondary storage unit.
• INFORMATION: This is an organized set of data placed in a Meaningful and Useful context for end
users; it is the finished product or the processed form of the raw data.

4. TYPE OF COMPUTERS
• ANALOG COMPUTER: These are used to measure physical-magnitude such as
temperature, pressure mileage Etc. They are used to do all manual work or they are
used for engineering purpose. They are continuous sound waves, e.g. Analogue
Telephone.
• DIGITAL COMPUTER: these perform mathematical operation, calculation and
commercial data processing. They are all electronics materials e.g. calculator,
mobile phone etc.
• HYBRID COMPUTER: these types of computers are, as the name suggests, a
combination of both Analogue and Digital computers. The Digital computers
which work on the principle of binary digit system of “0” and “1” can give very
precise results. But the problem is that they are too slow and incapable of large
scale mathematical operation Robotics and process control.

5. WHAT IS A SYSTEM
• A System is an organized set of related things put together to work as
one or achieve a particular goal.
• A computer system is a functional unit consisting of the keyboard,
monitor, system unit, mouse, printer etc.
• And other peripherals devices like the U.P.S, which means
uninterrupted power supply. The UPS is electrical device that is used to
store electric charge to be use by the user when there is an emergency
power failure from the generating machine.

6. DIFFERENT PARTS OF A COMPUTER

7. SYSTEM UNIT

8. SOFTWARE
This is the invisible aspect of computer system that we cannot see, touch
or identify instead, it is made up of coded instruction or program that
have been coded by either the manufacturer or Programmer for the
computer to follow them. It deals with the operational aspect of the
computer studies and those that are involve in as a faculty of study will
graduate as Software Engineer. Software can be of two types;
1. Application Software
2. System Software

9. Application Software
This is the day to day running program that is within
computer system that can be applied to perform
various tasks. E.g. MS-Word, MS-Access, MS-
PowerPoint, MS-Publisher Etc.

10. System Software
This is the decision-making department within the system, with the Aid
of an operating system. AN OPERATING SYSTEM: it is the master
computer software that helps to coordinate the flow of the computer and
also act as an interface (interpreter) between the user and the computer
itself.
FUNCTIONS OF THE OPERATING SYSTEM
• The operating system performs the following types of tasks:
• Coordinates processing with the help of the main memory
• Checks equipment malfunctions and displays error messages ü
Manages the stored on disks

11. SOFTWARE PROGRAMS
There are many software programs that can be installed in to the computer system
depending on the type of operation you want to perform or business you want to do.
This software includes: OPERATING SYSTEM: Like disk operating system (DOS),
Macintosh software, OS/2, UNIX, Netware, Windows with the different Versions (3.1,
windows 95, windows 98, windows 98 second edition, Windows Millennium, Windows
NT, Windows Professional, Windows XP, Windows Vista, Windows 7,Windows 8, Etc.
OFFICE PROGRAMS: Like Office 97, Office 2000 Professional, Office 2003, Office
2007, Office 2010 and Office 2013 (these yearly products Etc.
THE RELATIONSHIP BETWEEN HARDWARE AND SOFTWARE
• The relationship between the two is that, the hardware provides the environment e.g.,
Television set, Stadium, Video Cassette. Etc. whilst the software makes the thing to
happen e.g. athlete

12. BOOTING
Booting means to start up your computer that is giving power to the
system. When you power on a system, wait till the computer self-start to
point. During this time the computer will undergo a process known as
POST, SHORT FOR POWER ON SELF TEST where the computer will
test itself for all the peripheral that are connected to the main system
unit. (Input and output devices). When start up is completed, a DOS
prompt appears on the screen usually C:/> it can also display ICONS on
the screen called desktop, depending on the type of software installed in
your computer. DOS prompt indicate that DOS is ready for you to issue
commands. DOS prompt is also DOS signature indicating that any
operation conducted will be inside in a Active Drive, Like A: B: C: etc
Booting can be of two types, cool booting and warn booting.

13. COOL BOOTING
This is the process of starting your computer (giving power to your
system) by using the main switch. If the computer lacks the reset button,
you can turn off the power and turn it on again as many times as it
requires. This process of turning the computer on and off by using the
power switch is all about COOL BOOTING.

14. WARM BOOTING
This is the process of restarting your computer without turning the
power off. Punching or CLICKING the RESTART button on the system
unit could do this. If the computer lacks the restart button, the keyboard
could do warm booting. To carry out this task, you press the
CTRL+ALT+DEL keys together. There is no time wasting, warm booting
is faster because you trigger the reboot with CTRL+ALT+DEL, which is
refer to as Keyboard reboot. In this process of worm booting, the
computer restarts all RAM leaving them blank.

15. LOGGING IN AND CREATING USER ACCOUNTS
Logging in
• Start or Restart the Computer
• Select User Account
• Enter Password
• Login
Creating user accounts
• Open User Accounts Settings
• Create a New User Account
• Enter User Details
• Complete the Setup

16. NAVIGATING THE DESKTOP AND USER INTERFACE
Desktop Elements:
• Desktop Background:
The desktop is the primary screen that appears after logging in. It often contains a background image.
• Icons:
Icons represent shortcuts to files, folders, or applications. Double-click an icon to open the associated item.
• Taskbar:
The taskbar is usually located at the bottom of the screen. It contains the Start menu, open applications, system tray,
and clock.
• Start Menu:
Click the Start button in the bottom-left corner to access the Start menu. From here, you can open applications, access
settings, and shut down or restart the computer.
• System Tray:
The system tray, located on the right side of the taskbar, displays system icons (e.g., volume, network) and
notifications.

17. NAVIGATING THE DESKTOP AND USER INTERFACE
Navigating the Start Menu:
• Start Menu Search:
Use the search bar in the Start menu to quickly find applications, files, or settings by typing
keywords.
• All Apps:
Click "All apps" to see a list of installed applications.
• Live Tiles (Windows 10 and 11):
In Windows 10 and 11, the Start menu may include live tiles that display real-time information from
certain apps.

18. NAVIGATING THE DESKTOP AND USER INTERFACE
File Explorer:
• Accessing File Explorer:
Use File Explorer to browse and manage files and folders. You can open it by clicking the folder icon
on the taskbar or searching for "File Explorer" in the Start menu.
• Navigation Pane:
The left side of File Explorer contains a navigation pane to quickly access common locations like
Desktop, Downloads, Documents, etc.
• Address Bar:
The address bar at the top of File Explorer shows the current location. You can type paths or use it
for navigation.
• Quick Access:
Quick Access shows frequently used folders and recently accessed files.

19. NAVIGATING THE DESKTOP AND USER INTERFACE
Window Management:
• Minimize, Maximize, and Close:
Use the buttons in the top-right corner of windows to minimize, maximize, or close them.
• Task View (Windows 10 and 11):
Use Task View to see all open windows, virtual desktops, and switch between them.
• Snap Windows (Windows 10 and 11):
Drag a window to the side of the screen to snap it. This feature helps organize multiple windows side
by side.

20. NAVIGATING THE DESKTOP AND USER INTERFACE
Settings:
• Accessing Settings:
Open the Settings app from the Start menu or use the
keyboard shortcut Win + I.
• Control Panel:
For more advanced system settings, you can access the
Control Panel.

21. NAVIGATING THE DESKTOP AND USER INTERFACE
Desktop Shortcuts:
• Creating Shortcuts:
Right-click on a file, folder, or application and choose "Create shortcut" to place a shortcut on the
desktop.
• Customizing Desktop:
Right-click on the desktop to change the desktop background, display settings, and personalize the
desktop.

22. END NOTE