Introduction to Programming and Software Types

Programming and Source Code

• Programmers write source code in a high-level language (like C++).
• A compiler translates the source code into machine-readable code.
• The compiled code is usually distributed as an executable file (e.g., test.exe).
• It is typically impossible to reverse the compilation process and retrieve the original source code from the executable file.

Open and Closed Source Software

• Having the executable file (e.g., test.exe) allows users to run the program.
• Proprietary software is closed source, meaning the source code is not publicly available for modification.
• Open source software refers to software where the source code is accessible and users are allowed to modify it.
• Open source licenses usually require that improvements to the code be shared with the community.

System and Application Software

• System software manages the computer's hardware, facilitates interaction between hardware and users, and provides services for application programs.
• Application software performs specific tasks for users, such as word processing or web browsing.

Control Programs and BIOS

• Control programs include device drivers and firmware that govern the functionality of hardware connected to the computer.
• BIOS (Basic Input/Output System) is a firmware software that runs when a computer is first powered on.
• BIOS is stored on a non-volatile ROM chip on the motherboard, meaning it retains its data even when the computer is off.
• BIOS can be updated without removing the motherboard, allowing for easy upgrades.
• BIOS provides basic functionalities such as controlling hardware, processing input/output operations, and identifying available devices during startup.

BIOS UI and Functions

• A modern BIOS has a menu-based interface accessed by pressing a specific key during startup.
• Users can configure hardware, set the system clock, enable/disable components, select boot devices, and set password prompts through the BIOS UI.
• Power-on self-test (POST) is the first BIOS function, which identifies and checks available hardware for booting (e.g., processor, RAM, graphics card).
• BIOS locates the boot loader, a software stored on the boot device (e.g., hard disk), which is then loaded and executed to send control to the computer.

Operating System Overview

• An operating system is essential for any computer; it manages hardware, enables user interaction, provides services for applications, and coordinates their execution.
• Without an operating system, a computer is essentially useless because it lacks a consistent way for applications to interact with hardware.

Types of Operating Systems

• Real-Time Operating Systems (RTOS) are used for controlling machinery, instruments, and industrial systems. They typically have limited user interfaces and execute operations with precise timing.
• Single-user, single-task operating systems allow only one user to perform one task at a time.
• Single-user, multi-tasking operating systems (like those used on desktops and laptops), allow a user to run multiple programs simultaneously.
• Multi-user operating systems allow several users to access and work on the computer simultaneously.
• Distributed operating systems manage a group of independent computers, making them appear as a single system.
• Embedded operating systems are designed for small devices (like PDAs) and are optimized for efficiency and resource management.

Popular Operating System Distributions

• Microsoft Windows (10, 11, Server 2022) is a leading operating system for personal computers and servers.
• Apple macOS is the primary operating system for Apple computers.
• Linux distributions like Ubuntu are known for their open source nature and versatility.
• Android is a mobile operating system popular for smartphones and tablets.
• iOS is Apple's mobile operating system for iPhones and iPads.

Other Operating System Features

• User Interface:
  • Command line interface (CLI): User interacts using text-based commands.
  • Graphical user interface (GUI): User interacts using visual elements like icons and menus.
• Hardware Independence:
  • Application Programming Interface (API) acts as an intermediary between application software and the operating system.
• Task Execution:
  • Multitasking: Multiple tasks execute concurrently.
  • Multithreading: Multiple execution threads share resources within a single CPU core.
  • Multiprocessing: Multiple CPUs work in parallel within a single system.
  • Time-sharing: Resources are shared amongst multiple users via multiprogramming and multitasking.
  • Scalability: Ability to handle increasing workload with efficient resource allocation.
• Networking Capability:
  • Network operating system (NOS) supports network functionality and communication between computers.
• System Resource Access:
  • Protection mechanisms prevent unauthorized access to system resources.
• File Management:
  • Operations for creating, accessing, modifying, and deleting files and data on the computer.

Utility Software

• Utility software is system software designed to analyze, configure, optimize, or maintain a computer system.
• It facilitates operating system functionality, configures computer settings, enables programming language usage, and performs other helpful tasks.
• Utility software categories include tools for managing hardware and resources, antivirus protection, data compression, internet connection management, computer maintenance, and document protection.

Programming Software and Tools

• Programming tools are essential for developing and managing other programs and software.
• They include:
  • Programming languages (e.g., C++, Java, Python).
  • Source code editors (for writing and editing code).
  • Compilers (to translate high-level source code into machine language).
  • Interpreters (to directly execute program instructions without prior compilation).
  • Debuggers (to identify and fix errors in code).
  • Integrated development environments (IDE) (to provide a comprehensive development environment).

Programming Languages

• Programming languages are formal languages that communicate instructions to machines, primarily computers.
• They are strictly defined sets of rules enabling humans to express tasks for computers in an understandable format.

Programming Language Division

• Generations: Programming languages evolve across generations, each with distinct features and capabilities.
• Purpose: Languages can be categorized as general-purpose or specific to specific tasks.
• Paradigms:
  • Imperative: Code describes how to take actions.
  • Procedural: Code describes how to obtain desired results.
  • Declarative: Code expresses computational logic without specifying execution order.
  • Object-Oriented: Code organizes data and operations into objects, focusing on object interactions.
  • Functional: Code focuses on functions and their transformations, treating computation as evaluation of expressions.
  • Logical: Code uses logical rules and relationships to solve problems.

Compilers

• A compiler translates source code written in a high-level language into a lower-level language, typically machine code.
• Compilers usually produce executable versions of programs.
• Cross-compilers translate code for a different platform than the one running the compiler.

Decompilers and Source-to-Source Compilers

• Decompilers attempt to reverse the compilation process, converting low-level code into a higher-level representation.
• Source-to-source compilers translate code from one programming language to another, while retaining a higher level of abstraction.

Interpreters

• Interpreters execute program instructions directly without prior compilation.
• They are commonly used in scripting languages and web browsers for languages like JavaScript.
• Compiled code typically executes faster than interpreted code.

Linkers

• Linkers are programs that combine multiple object files into a single executable program.
• Object files are generated by compilers.
• They are also known as link editors or binders.

Debuggers

• Debuggers are computer programs that test and debug logical mistakes in programs.
• Program execution is the process of running a program.
• These errors occur during program execution.
• They are used to monitor the execution of programs step by step.

Integrated Development Environment (IDE)

• An IDE is a software suite that combines several programs to facilitate the development process.
• Programs include:
  • Text editors
  • Compilers
  • Debuggers
  • Integrators of library functions
  • Linkers

Application Software

• Application software enables users to perform specific tasks or solve problems.
• It performs tasks visible to the user.
• It's known for its intuitive and user-friendly interface.

Application Software Classification

• Application software can be classified as proprietary or off-the-shelf.
• Proprietary software is developed in-house or contracted out.
• Off-the-shelf software is purchased or rented, often in standard packages.

Proprietary Software

• It solves a specific problem or task.
• It can be customized for better control of results.
• Advantages:
  • Software usually fulfils user needs.
  • Enables flexibility during inspection and modification.
• Disadvantages:
  • Closed source software, meaning limitations exist.
  • Development is expensive and resource-intensive.
  • Higher risk of feature and performance issues.

Off-the-shelf Software

• General or function-specific application software
• Advantages:
  • Lower initial price and reduced risk of failure.
  • Well-tested software with fewer bugs.
• Disadvantages:
  • Users may pay for unnecessary functionalities.
  • Software may lack essential features needed by users.
  • May not align with current company work processes.

Software Suites

• Multiple software applications designed to work together.
• They often share common user interfaces.
• They can smoothly exchange data with each other.
• Suites offer lower prices compared to buying individual applications.

Application Software for Personal Use

• Designed to meet individual users' needs and enhance personal efficiency.

Word (Text) Processing

• Word processors automate text processing tasks.

This quiz covers essential concepts in programming, including source code, compilers, and the distinctions between open and closed source software. It also explores the roles of system and application software in computing. Test your knowledge on these fundamental topics in software development.