Lecture Notes: Computer Hardware and Software (Video Notes)

Open Source Software (OSS)

Definition: Software distributed freely with the source code available to anyone to read, modify, and distribute.
Examples: Linux, OpenOffice, VLC, GIMP
Key characteristics:
- Freedom to study how the program works
- Freedom to modify the program to suit needs
- Freedom to redistribute copies to others
- Freedom to distribute modified versions to the public
Distinction from proprietary software: OSS licenses usually require that source code be available and permit modification and redistribution; proprietary software typically restricts access to source code and modification.
Related licensing note (contextual): OSS licenses come in various forms (e.g., permissive vs copyleft) that govern how modifications and distributions are handled.

Definition: The physical components of a computer system.
Relationship to software: Hardware provides the physical substrate on which software runs; software instructs hardware what to do.
Broad categories within hardware:
- Central Processing Unit (CPU)
- Memory (RAM)
- Storage (not explicitly listed in transcript but commonly associated)
- Input/output devices (peripherals)

RAM (Random Access Memory)
- Function: Temporary storage used by the CPU to hold data and instructions currently in use
- Characteristics: Volatile memory (data is lost when power is removed)
CPU (Central Processing Unit)
- Function: The brain of the computer; executes instructions and coordinates operations
- Role: Core hardware component that performs computation
Input devices
- Examples from transcript: Keyboard, Flash drive (USB), Mouse
- Purpose: Allow users to feed data and commands into the computer
Output devices
- Examples from transcript: Monitor, Speakers, Printer, Scanner
- Purpose: Present results or data from the computer to the user or to other devices

System Software
- Purpose: Manages the computer system's resources and provides a platform for applications
- Examples (from transcript): Windows, Linux, macOS, Android
- Core role: Controls hardware, manages memory, processes, devices, and provides basic services to applications
Application Software
- Purpose: Programs used by the user to perform tasks
- Examples (from transcript): Word, Gmail, Excel, Netflix
- Examples of tasks: Document creation, emailing, data analysis, media consumption

Definition: A type of system software that manages computer hardware and provides common services for computer programs
Examples (from transcript): Windows, Linux, macOS, Android
Key responsibilities:
- Resource management (CPU time, memory, I/O)
- Scheduling and execution of processes
- File system management
- User interface provision and security controls
- Hardware abstraction to allow apps to run across different devices

How OSS relates to real-world computing:
- Encourages collaboration, transparency, and customization
- Enables users to inspect and modify software to fit needs
- Can affect security and update models depending on license and community practices
System software vs application software in practice:
- OS abstracts hardware and provides core services used by all programs
- Applications build on top of the OS to perform specific user tasks
Hardware–software interaction:
- CPU executes instructions issued by software
- RAM temporarily stores data and instructions for fast access during computation
- Input/output devices facilitate user interaction and data transfer