Fundamental Concepts of Computer Science

Fundamental Concepts

• Hardware: The physical components of a computer system, including the CPU, RAM, storage devices (hard drives, SSDs), input devices (keyboard, mouse), and output devices (monitor, printer).
• Software: The set of instructions that tells the hardware what to do. This includes operating systems (like Windows, macOS, Linux), applications (like word processors, web browsers, games), and programming languages (used to create software).
• Data: Raw facts and figures, or symbols that can be processed by a computer. This can be text, numbers, images, audio, or video.
• Information: Processed data that has meaning and can be used to make decisions or take actions. This transforms raw data into something useful.

Operating Systems (OS)

• Role: Acts as an intermediary between the user and the hardware, managing the resources of the computer and allowing other software to run.
• Key Functions:
  • Managing computer resources (CPU, memory, storage)
  • Providing a user interface (GUI or command-line)
  • Running applications
  • Handling input and output operations
  • Security (access control, authentication)
• Examples: Windows, macOS, Linux (and various distributions).

Central Processing Unit (CPU)

• Function: The "brain" of the computer, responsible for executing instructions.
• Components: Control unit (CU) and arithmetic logic unit (ALU).
• Speed: Measured in gigahertz (GHz). Higher GHz generally means faster processing.
• Multi-core: Modern CPUs often have multiple cores, enabling parallel processing (doing multiple tasks at once).

Random Access Memory (RAM)

• Function: Stores data and instructions that the CPU is currently using.
• Characteristics: Volatile memory—data is lost when the power is turned off.
• Capacity: Measured in gigabytes (GB). More RAM generally allows for running more programs simultaneously without slowing down.

Storage Devices

• Hard Disk Drives (HDDs): Magnetic storage that is relatively inexpensive but slower than SSDs.
• Solid State Drives (SSDs): Use flash memory and are significantly faster but more expensive than HDDs.
  • Types: SATA, NVMe.
• Cloud Storage: Storing data on remote servers accessible via the internet.

Input and Output Devices

• Input Devices: Allow users to give data to the computer (keyboard, mouse, scanner, microphone).
• Output Devices: Show or provide data from the computer (monitor, printer, speaker).

Networks

• Local Area Networks (LANs): Connect computers within a limited area (e.g., a home, office).
• Wide Area Networks (WANs): Connect computers over a larger geographic area (e.g., the internet).
• Internet: A global network of interconnected computers.

Data Representation

• Binary System: Computers use binary code (0s and 1s) to represent all data.
• Bits and Bytes: A bit is the smallest unit of data, a byte is 8 bits.
• Character Encoding: Systems for representing characters (letters, numbers, symbols) in binary code. (e.g., ASCII, Unicode)

Software Development

• Programming Languages: High-level languages (Python, Java, C++) allow programmers to write instructions for computers in a human-readable format.
• Compilers and Interpreters: Translate these high-level codes into machine code that the CPU can execute.
• Software Development Life Cycle (SDLC): A process that guides the creation of software, from planning to testing.

Cybersecurity

• Importance: Protecting computer systems and data from unauthorized access, use, disclosure, disruption, modification, or destruction.
• Threats: Viruses, malware, phishing, hacking, denial-of-service attacks.
• Protection: Firewalls, anti-virus software, strong passwords, secure coding practices.

Types of Software

• System Software: Controls the computer hardware (Operating Systems).
• Application Software: Programs designed for specific tasks (word processors, games).