Computer Science Test 2 Nddc Scholarship

Lossy compression reduces file size by permanently removing data that is least noticeable to the human eye or ear (common in JPEGs and MP3s). Lossless compression reduces size by mathematically reorganizing data without losing any information, allowing the original file to be perfectly reconstructed (common in ZIP files and text documents).

Data refers to raw, unorganized facts, figures, and symbols that have not yet been processed. Information is the result of taking that raw data and processing, organizing, or structuring it in a way that makes it meaningful and useful to a human user for decision-making or analysis purposes.

Secondary storage (like hard drives) must be non-volatile, meaning it retains data when power is lost. Because users need to store large amounts of data, these devices must be relatively low cost per gigabyte and provide enough speed to transfer files to the primary memory efficiently for processing.

Standard QWERTY keyboards used for desktop computers generally feature between 101 and 105 keys, depending on the region and the inclusion of specialized Windows or Function keys. This layout provides a comprehensive set of alphanumeric characters, navigation controls, and a dedicated numeric keypad for efficient data entry.

Windows includes several built-in utility programs known as 'Accessories,' such as Notepad for text editing, Calculator for math, and Paint for simple graphics. Corel Draw, however, is a professional third-party vector graphics software suite that must be purchased and installed separately from the operating system.

WYSIWYG refers to a user interface that allows the user to see what the final printed or published result will look like while the document is being created. In a WYSIWYG editor like Microsoft Word, the bold text or images you see on the screen appear exactly the same way when the document is printed.

Multimedia is the use of a computer to present and combine various forms of content, including text, graphics, audio, video, and animation, with links and tools that let the user navigate, interact, and communicate. It is a fundamental part of modern web design, education, and digital entertainment.

Menu-driven interfaces allow users to interact with a computer by selecting options from a list or visual icons. This is far more user-friendly than a command-line interface because it removes the burden of memorizing specific syntax and complex text-based commands, making the computer accessible to non-technical users.

The system clock is a microchip that regulates the timing and speed of all computer functions. It emits a continuous stream of electrical pulses, measured in Gigahertz (GHz), which act as a metronome for the CPU. Every instruction executed by the processor must happen in sync with these 'ticks,' ensuring that data moves through the system without collisions or timing errors.

Firmware is a specific class of system software that provides low-level control for a device's specific hardware. Unlike application software, which users interact with to perform tasks, firmware is embedded directly into hardware components like the BIOS chip on a motherboard. It serves as the essential foundation that allows the hardware to communicate with the higher-level operating system.