IT Fundamentals Pro 1.2

The Hexadecimal System

A base-16 numbering system that uses the letters A-F and digits 0-9 to signify values.

Unicode

A character code that enables most of the languages of the world to be symbolized with a special character identification.

Digital Data

A physical signal, such as text, numbers, graphics, or sound, interpreted by converting it into binary numbers.

The Binary System

A system in which numbers are represented using only the digits 0 and 1.

Vector Images

A vector image, such as a logo, that can be easily resized without loss of quality.

Sampling Rate

Another setting that affects sound recording quality is the sampling rate, or how many individual samples are taken each second. This rate is measured in hertz (Hz). For example, a sampling rate of one thousand samples per second is the same as one thousand hertz, or one kilohertz (kHz). Most modern sound recordings are made at 44.1 kHz.

RGB Display

Computers monitors are made up of tiny red, green, and blue lights. By varying the brightness of one or more of the lights, each pixel can display any color on the visible spectrum.

Encoding Text

Computers represent text by using 1s and 0s as stand-ins for physical signals, such as magnetic or electrical charge. The computer can encode text by assigning a unique binary code to each character.

Storage Space

Data storage usually refers to the number of bytes. Since bits and bytes are so small and can't store much information, we use the metric system to describe a lot of them together in groups. 1 kilobyte = 1024 bytes 1 megabyte = 1024 kilobytes 1 gigabyte = 1024 megabytes 1 terabyte = 1024 gigabytes

ASCII (American Standard Code for Information Interchange)

Developed in 1963; Seven-bit code; represents 128 different codes.

Byte

Eight bits together form a byte. The value of a single byte can range from 0 (eight 0s) to 255 (eight 1s)

Processing Speed

In 64-bit processors, computers can receive or send eight bytes of data at once. Each time the processor writes data to memory or reads data from memory is called a cycle. The base unit of measure is hertz (Hz). One hertz means one cycle per second. 1 kilohertz (KHz) = 1000 Hz 1 megahertz (MHz) = 1 million Hz 1 gigahertz (GHz) = 1 billion Hz

Encoding Integers

Integers can have a positive or negative value. With 32 bits, computers encode this by using the first bit for the sign, one for negative and zero for positive. Then, the remaining 31 bits are used to encode the number itself, giving us a range from about negative 2 billion to positive 2 billion.

Compression Artifact

Noticeable distortion of images, audio, or video due to problems decompressing the media.

Bit Depth

Recording programs have to decide how much memory they should allocate to store the value of each sample. The amount of memory used is called the bit depth. 8-bit sound uses eight bits (or one byte) to store the value of each sample. 16-bit sound uses two bytes per sample. Generally speaking, the better the bit depth, the better the sound.

Sample

Sound is caused by vibrating objects, which create pressure waves in the air. Digital sound recordings capture this continuous wave and divide it into discrete segments. Then, it assigns a value to each segment. A single segment's value is called its

Frame Rate

Speed at which video frames appears on a screen; measured by FPS (frames per second)

Raster Images

images created using thousands of pixels which cannot be easily resized without diminished quality. Ex: photographs

Decimal System

system of numbers based on 10

Color Depth

The number of colors per pixel that can be contained in an image.

Bit

The smallest unit of digital information. Each individual one and zero in a binary sequence is a bit.

Run Length Encoding

This compression method works by reducing the physical size of a repeating string of characters. The repeated string or 'run' is encoded with 2 bits. The first represents the number of characters in the run and the other gives the character.

Throughput

Throughput, or data transmission from one computer to another, usually refers to the number of individual bits that can be transmitted in one second. For example, a gigabit Internet connection can send a billion ones and zeroes every second.

Lossless Compression

a data compression algorithm that allows the original data to be perfectly reconstructed from the compressed data. GIF PNG PDF ZIP

Resolution

a measure of the clarity of an image

Lossy Compression

data compression techniques in which some amount of data is lost. This technique attempts to eliminate redundant information. JPG MP3 MP4