Paper 1: Data Representation Flashcards
(28 cards)
Binary
A number system using only two digits: 0 and 1. It’s the fundamental language computers understand because it represents the on/off states of electronic circuits.
Bit
The smallest unit of data in a computer, representing either a 0 or a 1. Think of it as a single light switch – either on or off.
Byte
A group of 8 bits. It’s a common unit for measuring data storage. For example, a single character (like a letter or number) often requires one byte of storage.
Kilobyte (KB)
Approximately 1,000 bytes (actually 1024). Used to measure small file sizes, like a short document.
Megabyte (MB)
Approximately 1 million bytes. Used for medium-sized files like photos or songs.
Gigabyte (GB)
Approximately 1 billion bytes. Used for larger files like videos or software.
Terabyte (TB)
Approximately 1 trillion bytes. Used for very large storage capacities, like hard drives or large backups.
ASCII
A standard way of representing text characters (letters, numbers, symbols) using numerical codes. Each character is assigned a unique number.
Unicode
A more comprehensive character encoding standard than ASCII. It can represent characters from almost all written languages in the world.
Sampling Rate (in sound)
The number of samples taken per second, measured in Hertz (Hz). A higher sampling rate results in a more accurate representation of the original sound.
Sample Resolution (in sound)
The number of bits used to represent the amplitude (loudness) of each sound sample. Higher resolution means more detail and better sound quality.
Pixel
The smallest unit of a digital image or graphic that can be displayed on a screen. Think of it as a tiny dot of color.
Color Depth (in images)
The number of bits used to represent the color of a single pixel. Higher color depth allows for a wider range of colors.
Resolution (in images)
The number of pixels in an image, often expressed as width x height (e.g., 1920x1080). Higher resolution means more detail in the image.
Lossy Compression
A data compression technique that permanently removes some data to reduce file size. This can result in a loss of quality, but the file becomes much smaller (e.g., JPEG for images, MP3 for audio).
Lossless Compression
A data compression technique that reduces file size without losing any original data. The original data can be perfectly reconstructed (e.g., ZIP files, PNG for some images).
List the common storage units in order from smallest to largest.
Bit, Byte, Kilobyte, Megabyte, Gigabyte, Terabyte
What is bit depth (resolution) in digital audio?
The number of bits used to store each measurement of the sound. More bits allow for a wider range of volume and finer details in the sound.
What factors affect the file size of a bitmap image?
The number of pixels in the image and the number of bits used to represent the color of each pixel.
What is the main purpose of data compression?
To make files smaller so they take up less storage space and can be transferred more quickly.
Why is data compression important?
Saves space on storage devices.
Reduces the amount of data that needs to be sent over networks.
Makes downloading and uploading files faster.
Give an example of a lossy compression method.
JPEG for images, MP3 for audio, MPEG for video.
Give an example of a lossless compression method.
ZIP for general files, PNG for images, FLAC for audio.
How is text represented in computers?
Each character (letters, numbers, symbols) is given a unique numerical code.
