Computer Basics Quiz

Computer Basics

• Hardware: Physical components like keyboards, monitors, disks, and chips
• Software: Programs and data used by computers
• Essential Components: Both hardware and software are crucial for computer function.

Main Components

• CPU (Central Processing Unit): Executes program instructions
• RAM (Main Memory): Stores active programs and data temporarily
• Input/Output Devices: Allow user interaction (e.g., monitors, keyboards, mice)
• Secondary Memory: Permanent storage (e.g., hard disks, USB drives)

Software Categories

• Operating System: Manages computer resources and activities
• Application Programs: Specific software for tasks (e.g., word processors, web browsers)

Data Representation

• Analog: Continuous representation of information
• Digital: Information represented in discrete pieces
• Storage: Computers store all data digitally, in the form of numbers.

Computer Architecture

• Memory Cells: Memory is divided into cells with unique addresses
• Bytes: Information stored in bytes (usually 8 bits)
• Storage Units: Computer storage capacity measured in units like KB, MB, GB, TB, PB.

Memory Types

• RAM (Main Memory): Volatile, direct access
• Secondary Memory: Non-volatile, direct or sequential access
• ROM (Read-Only Memory): Permanent storage

CPU (Central Processing Unit)

• Fetch-Decode-Execute Cycle: CPU follows this cycle to process instructions
• Components: Arithmetic/Logic Unit, Registers, Control Unit
• Speed: Measured in gigahertz (GHz)

Networks

• Connected Computers: Two or more computers sharing data and resources
• Network Addresses: Each computer has a unique network address
• File Servers: Central locations for shared programs and data

Network Types

• LAN (Local Area Network): Covers a small area
• WAN (Wide Area Network): Connects multiple LANs over larger distances

Internet

• Global WAN: A global network using TCP/IP protocols
• IP Addresses: Unique numerical addresses for computers on the internet
• Domain Names: Human-readable names for websites
• DNS (Domain Name System): Translates domain names to IP addresses

World Wide Web

• Browsers: Used to access web resources (e.g., Internet Explorer, Safari, Firefox).
• HTML: Structure for web documents.
• URLs (Uniform Resource Locators): Unique addresses for web resources.

Java Programming Language

• Origin: Created by Sun Microsystems in 1995
• Structure: Programs organized into classes containing methods and statements.
• main Method: Every Java application includes a main method.

Java Program Components

• Comments: Used to explain code purpose and steps.
• Identifiers: Words used in programs (letters, digits, underscores, dollar signs)
• Reserved Words: Predefined words with special meanings.

Program Development

• Writing Code: Creating code using a Java compiler.
• Translation: Converting code into executable bytecode
• Debugging: Identifying and fixing errors in code

Java Translation Process

• Compilation: Source code compiled into bytecode.
• Execution: Java Virtual Machine (JVM) executes the bytecode.
• Architecture Neutrality: Java code works on different systems.

Types of Errors

• Compile-time errors: Syntax errors detected by the compiler.
• Run-time errors: Errors during program execution.
• Logical errors: Errors in the program logic producing incorrect results.

Object-Oriented Programming Concepts

• Objects: Represent real-world concepts in code.
• Classes: Templates defining the structure (state) and behavior of objects.
• Inheritance: Creates new classes based on existing ones.

Indentation

• Purpose: Clearly shows the structure of the code, improving readability and debugging.
• Structure: New code blocks (enclosed in curly braces) are indented one level.
• Units: Usually spaces (2, 4, 8) or tabs.
• Consistency: Essential throughout a program
• Syntax in Java: Indentation itself is not part of Java syntax; it improves code structure and readability.