Programming Logic and Design - Chapter 1 Vocabulary

Hardware: The physical devices that comprise a computer system.
Central Processing Unit (CPU): Executes program instructions through a fetch-decode-execute cycle; requires a unique instruction set specific to the microprocessor brand (such as Intel, AMD, and Motorola).
ENIAC: Constructed in $1945$ to calculate artillery ballistic tables for the U.S. Army; featured a CPU measuring $8\,\text{feet}$ tall, $100\,\text{feet}$ long, and weighing $30\,\text{tons}$ .
Main Memory (RAM): Volatile temporary workspace where the computer stores active programs and data; loses contents when powered off.
Read-Only Memory (ROM): Nonvolatile memory containing system startup instructions that can be read but not modified.
Secondary Storage: Nonvolatile media for long-term data retention, including magnetic disk drives, solid-state drives (SSD), USB flash drives, optical discs (CDs and DVDs), and cloud storage remote servers.
Input and Output Devices: Input devices gather data (keyboard, mouse, touch screen, scanner, microphone, digital camera); output devices present formatted data (monitor, printer).

Bits and Bytes: Memory is organized into bytes, where $1\,\text{byte}$ consists of $8$ bits (binary digits). A bit holds a positive charge ( $1$ / on) or a negative charge ( $0$ / off).
Numeric Data: Encoded in the binary numbering system. A single byte stores integer values up to $255$ , while $2\,\text{bytes}$ store values up to $65535$ . Negative integers use two's complement, and real numbers use floating-point notation.
Text and Media: ASCII uses a set of $128$ numeric codes (e.g., the letter 'A' is stored as $65$ ); Unicode expands ASCII to support global character sets. Digital images consist of pixels, and digital sound is divided into samples.

Machine Language: Binary code ( $0$ s and $1$ s) directly executable by the CPU.
Assembly Language: Low-level programming language using mnemonic words translated into machine language by an assembler.
High-Level Languages: Languages designed for complex software development without needing hardware-level knowledge (e.g., Java, C++, Python, Visual Basic, Ada, Fortran, and C#).
Code Translation: Program source code contains key words, operators, and statements adhering to syntax rules. Translators convert source code into machine language via a compiler (generates a separate executable file) or an interpreter (translates and executes code on the fly).
Software Categories:
- System Software: Manages basic computer operations, including Operating Systems, Utility Programs, and Software Development Tools.
- Application Software: Programs designed for daily user tasks, such as word processing, spreadsheets, databases, and web browsers.