Computer Applications Technology (CAT) - Comprehensive Revision Guide
1. Core Concepts & Definitions
Hardware and Software Basics
Hardware: The physical components of a computer system.
o Central Processing Unit (CPU): Executes instructions, often called the "brain" of the
computer.
o Memory (RAM): Temporary storage for data being actively used. More RAM
generally means smoother multitasking.
o Storage Devices: Long-term storage devices like Hard Drives (HDDs), Solid-State
Drives (SSDs), and USB drives.
o Input Devices: Tools like keyboards, mice, and scanners that allow users to interact
with the computer.
o Output Devices: Devices like monitors, printers, and speakers that display or output
data.
Software: Programs and operating systems enabling computers to perform tasks.
o System Software: Includes the Operating System (OS), such as Windows, macOS, or
Linux, which manages hardware and software resources.
o Application Software: Programs designed to perform specific tasks, like Microsoft
Word for word processing or Photoshop for image editing.
o Utility Software: Helps maintain, analyze, and optimize a computer, such as antivirus
programs, file compression tools, and backup software.
2. Networking Fundamentals
Types of Networks:
o LAN (Local Area Network): Covers a small geographic area like an office or school.
Usually faster and more secure than larger networks.
o WAN (Wide Area Network): Spans a large geographic area, often using leased
telecommunication lines. The internet is the largest WAN.
o MAN (Metropolitan Area Network): Connects networks across a city or campus.
Network Topologies: Arrangement or layout of network devices.
o Bus Topology: All devices share a single cable; simple and low-cost, but prone to
slowdowns.
o Star Topology: Devices connected to a central hub. Easy to manage and
troubleshoot, but relies on the central device.
, o Mesh Topology: Every device connects to every other device; highly redundant but
costly.
Network Devices:
o Router: Connects different networks, directing data across them.
o Switch: Connects devices within a network, managing data flow efficiently.
o Access Point: Allows wireless devices to connect to a network, forming a Wi-Fi
hotspot.
3. Data & Information Management
Data vs. Information:
o Data: Raw, unorganized facts (e.g., numbers, text) without context.
o Information: Processed, organized data that has meaning (e.g., a report showing
trends).
Database Basics:
o Database: Organized collection of data.
o Table: A set of rows and columns within a database.
o Primary Key: A unique identifier for each record within a table (e.g., Student ID).
o Foreign Key: A field in one table that refers to the primary key in another,
establishing a relationship.
Database Management Systems (DBMS): Software for creating, managing, and manipulating
databases (e.g., MySQL, Microsoft Access).
SQL Basics:
o SELECT: Retrieve data from a database.
o INSERT: Add new records.
o UPDATE: Modify existing records.
o DELETE: Remove records.
Example SQL Queries:
Select all: SELECT * FROM Students;
Insert a record: INSERT INTO Students (Name, Age) VALUES ('John Doe', 20);
4. The Internet & Online Safety
Internet vs. World Wide Web (WWW):
o Internet: Global network of interconnected devices.
, o WWW: Collection of web pages accessible on the internet.
Cybersecurity Essentials:
o Virus: Malicious program that replicates and spreads, potentially damaging data.
o Firewall: Security system that monitors and controls network traffic, blocking
unauthorized access.
o Antivirus Software: Detects, prevents, and removes malware.
o Phishing: Scam in which attackers pose as legitimate entities to steal sensitive
information.
Online Privacy Tips:
o Use strong, unique passwords and consider password managers.
o Enable two-factor authentication (2FA) for an extra layer of security.
o Be cautious with sharing personal information and adjust privacy settings on social
media.
5. System Troubleshooting and Maintenance
Troubleshooting Common Issues:
o Slow Performance: Close unnecessary applications, check for malware, clear cache,
and consider upgrading RAM.
o Software Crashes: Restart the application, update the software, and check
compatibility.
o Internet Connectivity Issues: Restart the router, check network settings, and run a
network troubleshooter.
Maintenance Tips:
o Disk Cleanup: Frees up space by removing temporary and unnecessary files.
o Disk Defragmentation: Organizes fragmented files to improve speed (more relevant
for HDDs).
o Software Updates: Keeps system secure and improves functionality.
o Backup Data Regularly: Protects against data loss.
6. Exam Tips & Strategies
Understanding Key Terms: Be familiar with terminology, particularly in networking,
cybersecurity, and databases.
Troubleshooting Process: Know basic steps for resolving software, hardware, and
connectivity issues.
