information technology

CHAPTER 1: INFORMATION PROCESSING Definition Information processing is the collection, manipulation, storage and distribution of data to produce meaningful information. Information Processing Cycle 1. Input ○ Entering data into a computer system. 2. Processing ○ Converting raw data into meaningful information. 3. Output ○ Displaying processed information to users. 4. Storage ○ Saving data and information for future use. Source Documents A source document is an original document used to collect and record data before it is entered into a computer system. Examples of Source Documents: • Invoice • Receipt • Order Form • Application Form • Survey Questionnaire • Time Sheet Verification Verification is the process of checking that data entered into a computer matches the original source document. Types of Verification 1. Visual Verification ○ Comparing entered data with the original document. 2. Double Entry Verification ○ Data is entered twice and compared. 3. Proofreading ○ Checking data for mistakes before processing. Validation Validation is the process of ensuring that data entered into a computer is sensible, reasonable and follows predefined rules. Types of Validation 1. Range Check ○ Ensures data falls within a specific range. 2. Length Check ○ Checks the number of characters entered. 3. Presence Check ○ Ensures required fields are not left blank. 4. Format Check ○ Ensures data follows a specific format. 5. Type Check ○ Ensures the correct type of data is entered. Types of Errors 1. Transcription Error ○ Data is entered incorrectly. Example: 3567 entered as 3657. 2. Transposition Error ○ Digits or letters are reversed. Example: 4567 entered as 4657. 3. Omission Error ○ Information is left out. Example: John entered as Jhn. 4. Duplication Error ○ Data is entered more than once. CHAPTER 2: COMPUTER SPECIFICATIONS Definition Computer specifications are details that describe a computer's capabilities and performance. Common Hardware Specifications Processor (CPU) ● The brain of the computer. ● Executes instructions and processes data. Examples: • Intel Core i5 • Intel Core i7 • AMD Ryzen 5 RAM (Random Access Memory) ● Temporary memory used while programs are running. Examples: • 4 GB • 8 GB • 16 GB Storage Devices ● Store files and data permanently. Types: • HDD (Hard Disk Drive) • SSD (Solid State Drive) Operating System ● Software that manages the computer. Examples: • Windows • Linux • macOS Monitor Resolution ● Determines image quality and screen clarity. Example: • 1920 × 1080 CHAPTER 3: HARDWARE Definition Hardware refers to the physical components of a computer that can be seen and touched. Types of Hardware Input Devices Used to enter data into a computer. Examples: • Keyboard • Mouse • Scanner • Webcam • Microphone Output Devices Used to display information. Examples: • Monitor • Printer • Speakers • Projector Storage Devices Used to store data and information. Examples: • Hard Drive • SSD • Flash Drive • Memory Card Processing Devices Used to process data. Examples: • CPU • GPU CHAPTER 4: SOFTWARE Definition Software is a collection of programs and instructions that tell a computer what to do. Types of Software 1. System Software Manages computer hardware and software resources. Examples: • Windows • Linux • macOS 2. Application Software Designed to perform specific tasks. Examples: • Microsoft Word • Microsoft Excel • Microsoft PowerPoint 3. Utility Software Maintains and protects computer systems. Examples: • Antivirus Software • Disk Cleanup • Backup Software CHAPTER 5: CYBERSECURITY Definition Cybersecurity is the protection of computer systems, networks and data from cyber threats and unauthorized access. Common Cyber Threats Virus ● A malicious program that damages files and systems. Worm ● A program that spreads itself through networks. Trojan Horse ● Malicious software disguised as legitimate software. Phishing ● Fake emails or websites used to steal personal information. Hacking ● Unauthorized access to a computer system. Cybersecurity Measures • Use strong passwords. • Install antivirus software. • Keep software updated. • Use a firewall. • Enable two-factor authentication. • Avoid suspicious websites and links. CHAPTER 6: COMPUTER NETWORKS Definition A computer network is a collection of interconnected computers that share resources and information. Types of Networks LAN (Local Area Network) ● Covers a small geographical area. Example: A school computer laboratory. MAN (Metropolitan Area Network) ● Covers a city or large town. WAN (Wide Area Network) ● Covers large geographical areas. Example: The Internet. Transmission Media Guided Media (Wired) 1. Twisted Pair Cable ○ Commonly used in LANs. 2. Coaxial Cable ○ Used for television and internet connections. 3. Fibre Optic Cable ○ Uses light signals for high-speed communication. Unguided Media (Wireless) 1. Radio Waves ○ Used for Wi-Fi. 2. Microwaves ○ Used for satellite communication. 3. Infrared ○ Used in remote controls. Network Hardware Router ● Directs data between networks. Switch ● Connects devices in a LAN. Hub ● Sends data to all connected devices. Modem ● Connects a computer to the Internet. Network Interface Card (NIC) ● Allows devices to connect to a network. CHAPTER 7: WEB TECHNOLOGIES Definition Web technologies are tools and techniques used to create and maintain websites and web applications. Important Terms Website ● A collection of related web pages. Web Page ● A single page within a website. Browser ● Software used to access websites. Examples: • Google Chrome • Mozilla Firefox • Microsoft Edge URL ● The address of a web page. Search Engine ● A tool used to find information on the Internet. Examples: • Google • Bing HTML ● HyperText Markup Language used to structure web pages. CSS ● Cascading Style Sheets used to style web pages. JavaScript ● Programming language used to add interactivity to web pages. CHAPTER 8: SPREADSHEETS Definition A spreadsheet is software used to organize, calculate and analyze data in rows and columns. Formatting Features • Bold • Italics • Underline • Font Colour • Cell Shading • Borders • Alignment • Number Formatting Relative Reference A cell reference that changes when copied. Example: =A1+B1 When copied down: =A2+B2 Absolute Reference A cell reference that remains fixed when copied. Example: =$A$1+$B$1 IF Function Used to make decisions based on conditions. Syntax: =IF(condition,value_if_true,value_if_false) Example: =IF(B2>=50,"Pass","Fail") Sorting The process of arranging data in order. Types: • Ascending Order (A-Z) • Descending Order (Z-A) Charts 1. Column Chart 2. Bar Chart 3. Line Chart 4. Pie Chart CHAPTER 9: DATABASES Definition A database is an organized collection of related data stored electronically. Table A collection of related data arranged in rows and columns. Field A single category of information in a table. Examples: • Name • Age • Address Record A complete set of related fields about one person, place or thing. Data Types Text ● Stores letters and words. Number ● Stores numerical values. Date/Time ● Stores dates and times. Currency ● Stores monetary values. Boolean ● Stores Yes/No or True/False values. Primary Key A field that uniquely identifies each record in a table. Example: Student ID Relationships One-to-One ● One record relates to one other record. One-to-Many ● One record relates to many records. Example: One teacher teaches many students. Many-to-Many ● Many records relate to many records. Example: Students take many subjects and subjects have many students. IMPORTANT DEFINITIONS FOR EXAMS Information Processing – The collection, manipulation, storage and distribution of data to produce meaningful information. Hardware – The physical components of a computer that can be seen and touched. Software – A collection of programs and instructions that tell a computer what to do. Verification – The process of checking that data entered matches the original source document. Validation – The process of ensuring that data entered is sensible and follows rules. Cybersecurity – The protection of computer systems and data from cyber threats. Database – An organized collection of related data stored electronically. Field – A single piece of information in a database table. Record – A collection of related fields about one person, place or thing. Primary Key – A field that uniquely identifies each record in a database table. LAN – A network that covers a small geographical area. WAN – A network that covers a large geographical area.

Information Processing

The collection, manipulation, storage and distribution of data to produce meaningful information.

Input

Entering data into a computer system.

Processing

Converting raw data into meaningful information.

Output

Displaying processed information to users.

Storage

Saving data and information for future use.

Source Document

An original document used to collect and record data before it is entered into a computer system.

Types of Source Documents

Invoice, Receipt, Order Form, Application Form, Survey Questionnaire, Time Sheet.

Verification

The process of checking that data entered into a computer matches the original source document.

Types of Verification

Visual Verification, Double Entry Verification, Proofreading.

Validation

The process of ensuring that data entered into a computer is sensible and follows predefined rules.

Types of Validation

Range Check, Length Check, Presence Check, Format Check, Type Check.

Types of Errors

Transcription Error, Transposition Error, Omission Error, Duplication Error.

Computer Specifications

Details that describe a computer's capabilities and performance.

Common Hardware Specifications

Processor (CPU), RAM, Storage Devices, Operating System, Monitor Resolution.

Types of Hardware

Input Devices, Output Devices, Storage Devices, Processing Devices.

Types of Software

System Software, Application Software, Utility Software.

Cybersecurity

The protection of computer systems, networks and data from cyber threats.

Common Cyber Threats

Virus, Worm, Trojan Horse, Phishing, Hacking.

Types of Networks

LAN (Local Area Network), MAN (Metropolitan Area Network), WAN (Wide Area Network).

Transmission Media

Guided Media (Wired) and Unguided Media (Wireless).

Web Technologies

Tools and techniques used to create and maintain websites and web applications.

Spreadsheet

Software used to organize, calculate and analyze data in rows and columns.

Database

An organized collection of related data stored electronically.

Field in a Database Table

A single category of information in a table.

Record in a Database

A complete set of related fields about one person, place or thing.

Primary Key

A field that uniquely identifies each record in a table.

LAN

A network that covers a small geographical area.

WAN

A network that covers a large geographical area.