Introduction
A computer isan electronic device
that accept data (input) and, process
data arithmetically and logically,
produce Information (output).
It is divided into two main categories:
Hardware Software
5.
COMPUTER HARDWARE
Hardwareis the physical aspect of
computers, telecommunications, and
other devices.
It includes not only the computer
proper but also the cables, connectors,
power supply units, and peripheral
devices such as the keyboard, mouse,
audio speaker, and printers.
CENTRAL PROCCESSING UNIT( CPU )
It is the brains of the computer.
Most of calculations take place
here.
Two typical components of a CPU are
1. Arithmetic Logic Unit ( ALU )
2. Control Unit ( CU )
MOTHERBOARD
Is the main circuit of a microcomputer.
It contains the CPU, memory, expansion
slots and all the controllers required to
control standard hardware devices.
8.
RANDOM ACCESS MEMORY( RAM )
RAM is the place in a computer where the
operating system, application programs,
and data in current use are kept.
It is a temporary and can be compared to
a person's short - term memory
READ ONLY MEMORY ( ROM )
It is a technology that allows you to
write data only once. After the data
has been written, you can read it an
unlimited number of time.
9.
INPUT HARDWARE
Keyboard
Mouse
Scanner
Common input hardware are :
Input hardware consists of external
devices by which we give information
and instructions to the computer.
10.
KEYBOARD
The setof typewriter-like keys that enables to
you enter data into a computer.
MOUSE
A device that controls the movement of the
cursor or pointer on a display screen.
SCANNER
A device that can read text or illustrations
printed on paper on translate the information
into a form the computer use.
11.
OUTPUT HARDWARE
Output hardwareconsists of internal and external
devices that transfer information form the computer's
CPU to the computer user.
Common output hardware are :
Monitor
Printer
Speaker
12.
MONITOR
A displayscreen used to present output from a
computer, video camera, VCR or other video
generator.
PRINTER
In computers, a printer is a device that accepts text and
graphic output from a computer and transfers the
information to paper.
SPEAKER
Speakers or headphones to an output port to hear the
audio produced by the computer.
13.
Common devices are:
Modem
LAN Card
CONNECTING HARDWARE
Connecting device allow hardware devices to
communicate with each other.
14.
MODEM
Modems connecta personal or
portable computer to dial-up
networks through a regular
telephone line.
LAN CARD
A local area network ( LAN ) card is
used to provide wireless internet
access to computer users in home or
roaming networks.
15.
STORAGE HARDWARE
A computerstorage device is any type of
hardware that stores data. Some common
storage devices are :
Hard Disc
Floppy disc
CD ROM
16.
HARD DISC
Amagnetic disk on which you can store computer
data . The term hard is used to distinguish it from a
soft , or Floppy disk.
FLOPPY DISC
A flexible plastic disk coated which magnetic Material and
covered by a protective jacket , used primarily by computers
to store data magnetically .
CD ROM
A CD – ROM is a CD that can be read by a computer
with an optical drive.
17.
COMPUTER SOFTWARE
Aset of instructions that enables
physical components of a
computer to work in a
synchronize way is known as
software.
This set of instruction is often
called of program.
Computers cannot do any useful
work without instructions from
18.
•TYPES OF SOFTWARE
Computersoftware is also divided in four
major types:
System software
Programing software
Application software
Utility software
19.
SYSTEM SOFTWARE
System softwarehelps in running the
computer hardware and the
computer system .
Main system soft wares are :
Operating systems
Device drivers
20.
DEVICE DRIVERS
Incomputing, a device driver is a computer program allowing
higher-level computer programs to interact with a hardware device
OPERATING SYSTEMS
An operating system is an interface between hardware and user;
it is responsible for the management and coordination of
activities and the sharing of the limited resources of the
computer .
21.
PROGRAMMING SOFTWARE
This isone of the most commonly known and popularly used forms of computer
software. These software come in forms of tools that assist a programmer in
writing computer Programs.
The tools that help the programmers in instructing a
computer system include:
Text
Editors
Compilers
Interpreters
22.
APPLICATION SOFTWARE
It enablesthe users to accomplish certain specific tasks. Following are the types
of application software.
Presentation Graphics Software
Allows users to create visual presentation. Example MS Power Point
Database Software
Allows users to store and retrieve vast amount of data. Example: MS Access
Spreadsheet Software
Allows users to create document and perform calculation. Example: MS Excel
Word Processing Software
Allows users to create, edit a document. Example- MS Word
Web Browsing Software
It allows one to surf the Web. Example- Google Chrome
23.
UTILITY SOFTWARE
Utility softwarehelps in the management of computer hardware and
application software. It performs a small range of tasks. Some typical
examples of utility software are
Disk Defragmenters
It detect computer files whose contents are stored on the hard disk in
disjointed fragments, and move the fragments together to increase efficiency.
Backup
This utility make a copy of all information stored on a disk, and restore
either the entire disk or selected files
Disk Partitioner
It divide an individual drive into multiple logical drives, each with its own file system
which can be mounted by the operating system and treated as an individual drive.
ANTI-VIRUS
These utilities scan computer for viruses.
Editor's Notes
#4 "Electronic device" – A computer runs on electricity and is made of circuits and components like the CPU, memory, etc.
"Accepts data (input)" – This means the computer takes in raw data from input devices like a keyboard, mouse, touchscreen, or even a microphone.
"Processes data arithmetically and logically" –
Arithmetically: Doing math operations like addition or subtraction.
Logically: Making decisions based on conditions (e.g., "if this, then that").
This processing happens in the CPU (Central Processing Unit).
"Produces information (output)" – After processing, the computer gives you results, which could be displayed on a monitor, printed on paper, played as sound, etc.
Example:
If you type "2 + 3" into a calculator app:
Input: You type the numbers and symbol.
Processing: The CPU does the math.
Output: The screen shows "5" — that's the information.
#5 means that hardware refers to the tangible, touchable parts of technology—anything you can physically handle or see, as opposed to software, which is the invisible instructions and code that make the hardware operate.
Computers: Hardware includes the CPU, monitor, keyboard, mouse, hard drive, RAM, motherboard, etc.
Telecommunications: This includes phones, routers, modems, cables, and towers.
Other devices: This could refer to tablets, smartwatches, printers, game consoles, and more.
In short, hardware is what the software runs on
#6 These are the physical parts inside the computer that work together to make it function.
Analogy:
Think of internal hardware components like the parts of an engine inside a car:
The engine (CPU) does the work.
The fuel (RAM) supplies the power needed for immediate action.
The wires and connectors (motherboard) link all the parts together.
The gas tank (storage) holds the fuel for later use.
#7 CPU (Central Processing Unit)
Definition: The CPU is often called the "brain" of the computer because it controls and processes all instructions given to the computer.
What does the CPU do?
Fetches instructions (from RAM).
Decodes them (figures out what needs to be done).
Executes them (performs calculations or sends commands).
Stores the results (often back in RAM).
This is called the Fetch-Decode-Execute Cycle — and it happens millions or even billions of times per second.
Analogy:
Think of the CPU like a chef in a kitchen:
The RAM is the counter with ingredients (data).
The CPU (chef) reads a recipe (instructions), gathers the ingredients, prepares the dish (processes the data), and puts it on the table (sends output).
Key Components Inside the CPU:
ALU (Arithmetic Logic Unit) – does math and logical operations.
CU (Control Unit) – directs the flow of data and instructions.
Motherboard
Definition: The motherboard is the main circuit board inside a microcomputer (like a desktop or laptop).
It connects and allows communication between all of the computer's essential components.
Key Functions of the Motherboard:
Holds the CPU: The central processing unit (CPU) is mounted on the motherboard and communicates directly with it.
Connects to RAM: RAM sticks are inserted into slots on the motherboard for data storage and retrieval.
Houses Expansion Slots: The motherboard has PCI or PCIe slots where you can add components like graphics cards, network cards, and sound cards.
Power Distribution: It distributes power from the power supply to all the parts connected to it.
Communication Pathways: The motherboard has various buses and connectors that allow data to flow between the CPU, memory, and other components.
Analogy:
Think of the motherboard like a city's main highway system:
The CPU is like the city's control center.
RAM is like the temporary storage areas for items being used.
Peripheral devices (keyboard, mouse, etc.) are like the outlying areas connected to the city.
The motherboard (the highway system) allows all of these components to communicate and work together.
#8 What is RAM?
RAM (Random Access Memory) is a type of temporary memory in a computer.
Temporary: RAM loses all its data when the computer is turned off
Key points in your sentence:
"The place in a computer" – RAM is a physical chip or set of chips inside the computer.
"Where the operating system, application programs, and data in current use are kept" – This means that when you turn on your computer and open programs (like a browser or Word), they are loaded into RAM so the CPU can access them quickly.
Why is RAM important?
It allows your computer to work fast by keeping needed info easily accessible.
The more RAM you have, the more programs or data your computer can handle at once without slowing down.
Example:
If you're editing a photo:
The photo file, the editing software, and even parts of the operating system are loaded into RAM.
When you save the file, it goes to the hard drive (permanent storage), but while you're working, it's in RAM.
ROM (Read-Only Memory)
Definition: ROM is a type of non-volatile memory that stores data permanently.
Once data is written to ROM, it cannot be changed or erased easily, and it can be read an unlimited number of times.
Key Features:
Write Once, Read Many: Data is written during manufacturing or setup and then stays fixed.
Non-volatile: Data is not lost when the computer is turned off (unlike RAM).
Used for:
Storing the BIOS or firmware – the basic instructions the computer uses to start up.
Embedded systems (like those in microwaves, washing machines, etc.).
Analogy:
Think of ROM like a book that's printed and sealed:
You can read the book as many times as you want.
But you can’t change the words inside it after it's printed.
#9 Input Hardware
Definition: Input hardware includes the external devices we use to send data or instructions into a computer.
Key Points:
These devices let the user communicate with the computer.
They are called input devices because data flows into the system.
Analogy:
Think of input hardware like a remote control for a TV:
You press buttons (give input), and the TV reacts.
In the same way, input devices send commands to the computer so it knows what to do.
#10 Keyboard
Definition: A keyboard is an input device made up of a set of typewriter-like keys that allows you to enter letters, numbers, symbols, and commands into a computer.
Used for:
Typing text in documents or emails.
Controlling software through shortcuts (e.g., Ctrl+C to copy).
Entering commands in programming or command-line interfaces.
Mouse
Movement Tracking: Moves the pointer across the screen as you move the mouse on a surface.
Types:
Wired mouse – connects via USB.
Wireless mouse – connects via Bluetooth or a USB receiver.
Optical mouse – uses a light sensor to detect movement.
Scanner
Definition: A scanner is an input device that reads text, images, or illustrations printed on paper and converts them into a digital format that the computer can store, display, or edit.
#11 Output Hardware
Definition: Output hardware includes internal and external devices that take data processed by the computer’s CPU and present it to the user in a readable or usable form.
Key Purpose:
To deliver results of the computer’s operations — such as text, images, sound, or physical output — so the user can see, hear, or use them.
Analogy:
Think of output hardware like a translator or messenger:
The CPU does the work behind the scenes.
The output devices show or deliver the results to you, the user — like a TV showing the news after the newsroom finishes reporting.
#12 Monitor
Definition: A monitor is an output device that displays visual information from a computer or other video source such as a video camera, VCR, or gaming console.
Key Functions:
Displays output from the computer, such as:
Text documents
Videos and images
Software interfaces
Games and animations
Acts as the primary way users see what the computer is doing.
Analogy:
A monitor is like a window into the computer:
It lets you see what’s happening inside the system — just like a TV shows you a program, the monitor shows your computer’s work.
Printer
Definition: A printer is an output device that takes text and graphic output from a computer and transfers that information onto paper, producing a hard copy.
Key Functions:
Converts digital documents, images, or data into physical copies.
Can print in black-and-white or color, depending on the printer.
Speakers or Headphones
Definition: Speakers and headphones are audio output devices that connect to a computer’s audio output port to let you hear the sound the computer produces, such as music, system alerts, voice, or video soundtracks.
#13 Connecting Devices
Definition: Connecting devices are components that allow different hardware devices to communicate with each other by transmitting data, power, or signals.
Key Roles:
Enable communication between internal components (like CPU and RAM) or external devices (like printers, monitors, or USB drives).
May be physical connectors, cables, or interface ports.
Analogy:
Think of connecting devices like bridges and roads in a city:
They let cars (data and power) travel between buildings (devices), so everything stays connected and functional.
#14 In Modern Context:
Nowadays, most computers come with built-in Wi-Fi NICs for wireless internet access, so external cards are mostly used for upgrades or when you need a specific type of connection (e.g., faster Ethernet speeds).
Modem
Definition: A modem is a device that connects a personal or portable computer to the internet by converting digital data from the computer into analog signals for transmission over a telephone line, and vice versa.
Key Points:
The word modem stands for Modulator-Demodulator:
Modulates digital data into analog signals for sending.
Demodulates incoming analog signals back into digital form.
Traditionally used for dial-up internet connections via regular phone lines.
Speeds were relatively slow (up to 56 kbps), and only one device could use the phone line at a time.
Modern Use:
Today, broadband modems (like DSL, cable, or fiber modems) are used instead of dial-up.
These modern modems are often combined with routers for Wi-Fi and multiple device access.
Definition: A LAN card, also known as a Network Interface Card (NIC), is a hardware component that allows a computer to connect to a Local Area Network (LAN). This could either be through a wired connection (Ethernet) or a wireless connection (Wi-Fi).
Key Functions:
Wired LAN: It connects a computer to a network via an Ethernet cable for high-speed internet and local networking.
Wireless LAN (Wi-Fi): For wireless internet access, the NIC allows the computer to connect to Wi-Fi networks within a range, such as home routers or public hotspots.
#15 Computer Storage Device
Definition: A computer storage device is any hardware that is used to store digital data, such as files, documents, images, videos, or software, either temporarily or permanently.
#16 Why "Hard" vs. "Floppy"?
Floppy disks were flexible, thin, and could easily be bent or damaged. They were much smaller in storage capacity (usually just a few megabytes).
Hard disks are rigid and more durable, offering larger storage capacities and faster access speeds.
Hard Disk Drive (HDD)
Definition: A hard disk drive (HDD) is a magnetic storage device used to store digital data on spinning disks coated with a magnetic material. The term "hard" distinguishes it from a floppy disk, which is a soft, flexible disk used in older computers.
Floppy Disk
Definition: A floppy disk is a flexible plastic disk coated with magnetic material and encased in a protective jacket. It was used primarily by older computers for storing and transferring data magnetically.
Uses:
Data Transfer: Floppy disks were used to transfer data between computers before the rise of USB drives and cloud storage.
Software Installation: Many early software applications were distributed on floppy disks.
Backup Storage: People used floppy disks for backup before other storage media like CDs and external hard drives became popular.
CD-ROM (Compact Disc Read-Only Memory)
Definition: A CD-ROM is a type of optical disc that stores data in a read-only format. It can be read by a computer with an optical drive (such as a CD/DVD drive), but the data on the disc cannot be modified or written to by the user.
Key Features:
Read-Only: Once data is written to the CD, it cannot be changed or erased. This is why it's called "Read-Only Memory."
Storage Capacity: Typically holds 700 MB of data, which is about 80 minutes of audio or a combination of files like software, documents, and media.
#17 Computer Software
Definition: Software refers to a set of instructions or programs that tell a computer's hardware (physical components) how to perform specific tasks. It acts as a bridge between the hardware and the user, enabling them to work together in a synchronized way.
Key Features:
Non-Physical: Unlike hardware, software consists of lines of code or programs that cannot be physically touched or seen, but they control and enable the hardware to do useful work.
How It Works:
Instructions: Software sends commands to the hardware components (CPU, RAM, storage devices) to execute tasks, such as opening a file, displaying an image, or processing data.
Synchronization: The software ensures that all the hardware components work together efficiently. For example, the operating system coordinates the CPU's work with the RAM to load a program, access storage, and display output on the screen.
Analogy:
Think of software as the director of a play, and the hardware as the actors:
The director (software) gives instructions on what the actors (hardware) should do and when to do it, ensuring that everything runs smoothly and the play (the computer system) functions as intended.
#19 Definition: System software is a type of software designed to manage and control computer hardware so that the computer system can operate efficiently. It provides the foundation for running application software and acts as an intermediary between hardware and user applications.
Why It’s Important:
Without system software, a computer would be inoperable because there would be no way to manage the interaction between hardware and software.
It also ensures that the system operates efficiently, securely, and without errors.
Analogy:
Think of system software like the conductor of an orchestra:
The hardware components (CPU, memory, etc.) are like the musicians playing their instruments.
The system software (like the operating system) is the conductor who directs all the musicians, making sure they play in harmony and follow the same rhythm, allowing the performance to go smoothly.
#20 Types of System Software:
Operating System (OS):
The most important system software that manages hardware and software resources.
Examples: Windows, macOS, Linux.
Functions include task management, memory management, file management, device control, and providing a user interface.
Device Drivers:
Small programs that allow the operating system to communicate with hardware devices like printers, graphics cards, and network adapters.
Example: A printer driver allows the computer to send print jobs to the printer.
#21 Programming Software
Definition: Programming software consists of tools and applications that help programmers write, test, debug, and maintain computer programs. It provides the necessary environment and resources to create software using programming languages.
Key Functions:
Writing code in different programming languages (e.g., Python, Java, C++)
Editing and formatting source code
Compiling and converting code into machine-readable form
Debugging to find and fix errors
Testing software to ensure it behaves as expected
Analogy:
Think of programming software like a toolbox for a builder:
The programmer is the builder, and the software tools (editor, compiler, debugger) are like hammers, levels, and saws used to build a house (the program).
#22 Application Software
Definition: Application software is a type of computer program designed to help users perform specific tasks such as writing documents, browsing the internet, editing photos, or managing data.
It runs on top of system software (like the operating system) and is tailored to serve user needs.
#23 Utility Software
Definition: Utility software is a type of system software that helps maintain, analyze, optimize, and protect a computer. It assists in the management of hardware, the smooth functioning of the operating system, and the support of application software by performing specific tasks.
Key Characteristics:
Performs specialized functions like cleaning up storage, scanning for viruses, or managing files.
Usually operates in the background or alongside other software.
Supports both system health and user efficiency.
Analogy:
Utility software is like the maintenance crew of your computer — it keeps things running smoothly, cleans up clutter, guards against threats, and ensures everything works efficiently.