Units of Measurement

For reference, some computer-related units of measurement and other measurement-related terms that you will encounter eventually.

Bit (b): binary digit. The smallest unit of data.Either a 0 or an 1.

Byte (B): exactly 8 bits, e.g. 01010101 is a byte. (in very unusual cases, it can mean a different amount of bits.)

Pixel (px, p, or P): the smallest unit of colored area of a computer image.

Hertz (Hz): cycles per second. How often a process is repeated in one single second.

Kilo-, Mega-, Giga-, Tera- (K, M, G, T): prefixes of scale meaning 1000¹, 1000², 1000³, 1000⁴. For example, 2 kilobytes (2KB) means 2000 bytes; 4 megapixels (4MP) means 4 million pixels (4000000 pixels, or 4×1000², or 4×1000×1000); 3 gigahertz (3GHz) means 3 billion times per second.

Kebi-, Mebi-, Gibi-, Tebi- (Ki, Mi, Gi, Ti): prefixes of scale meaning 2¹⁰, 2²⁰, 2³⁰, 2⁴⁰. For example, 1 kebibyte (1KiB) means 1024 bytes, while 1 mebibit (1Mib) means 1048576 bits. These are roughly the same thing as the units above.

Celsius degrees (°C): a measurement of temperature, used when measuring how hot processors (CPU, GPU) become as they process more data. Some processors get damaged at temperatures above 100°C (or 212°F (Fahrenheit degrees).

Watts (W): a measurement of how much electrical energy is transferred in one second. As you add parts to your computer, it requires more energy to keep them powered, which means more watts. Generally, having a mid-range dedicated graphics card means you'll need a 500W power supply, for example.

Volts (v): a measure of the general direction and scale of an electric current across two points. For example, -127v means one direction, while +127v means the opposite direction, both at the same scale. The electricity on your outlet is is AC (alternating current), and has a voltage such as ±127v. This means it alternates from -127v to +127v many times per second. Electronic components use a rectifier to convert this AC current into DC (direct current), which is always one direction, e.g. +5v.

Millisecond (ms): a thousandth of a second, typically found in load times related to the Internet, e.g. 100ms is one tenth of a second.

Microsecond (μs): a millionth of a second, typically used in times related to processors.

Other Measurement-Related Terms

x: used in 2D dimensions, e.g. 100x200px is an image of 100 pixels of width by 200 pixels of height.

Comma: used in 2D coordinates, e.g. 100,200 refers to the pixel that a point 100 pixels from the left, 200 pixels from the top.

FPS: frames per second. In one second, how many frames have been rendered (in a game), or were supposed to be rendered (in a video).

Bits per pixel (bpp): the amount of bits it takes to store the color data of one pixel of an image on average, e.g. 8bpp, 24bpp, or 32bpp. Uncompressed, RGB images are typically 24bpp.

480p, 720p, 1080p: refers to video sizes with widths of 480 pixels of width, 720 pixels of width, and 1080 pixels of width, respectively.

Ping: the time it takes for data from your computer to reach another computer on the Internet, typically a server, and come back. The time it takes to get a response.

Lag: term used whenever something that should be almost instantaneous takes a while, be it ping or the time it takes for the computer to respond to your input.