A batch file is a text file that contains a series of scripted commands that you would normally type manually at the command prompt. The file is generally read line-by-line, but you can create more complicated scripts that check for a series of conditions and jump to another point in the file and resume processing from there. Many of the commands, like copy or move are built into the command prompt, but you can also use command-line applications as well.
Multiplexing, also known as muxing, is when multiple analog or digital signals are combined into one signal over a shared medium, to use the most out of that connection. For instance, several telephone calls can be carried over a single wire. Devices that perform multiplexing are called multiplexers (MUX) or a device doing the reverse is called a demultiplexer (DEMUX). Inverse multiplexing (IMUX) does the opposite, and takes one data stream and converts it into multiple data streams that can be broadcast simultaneously over more than one communication channel and then combined back together.
Signal-to-noise ratio is a measure that compares the level of a signal to the level of background noise, to see how strong the signal actually is. The same phrase is sometimes used to refer to the amount of useful information to false information in an online exchange–for instance, if somebody says that the signal-to-noise ratio is low on a forum or online community, they usually mean that there is a lot more spam and off-topic nonsense than actually useful posts. A ratio of high would mean a good signal, whereas low means a bad signal.
The refresh rate is the number of times per second that display hardware re-draws the data on the screen, which is different from the number of unique frames, or images, that are displayed. For instance, movies are filmed at a rate of 24 frames per second, but an LCD TV display will refresh the screen more often–the refresh rate is usually from 60 to 240 times per second. Because 60 is not divisible by 24, movies played on a 60 hertz refresh rate set are not perfectly smooth, but a 120 hertz or 240 hertz TV will display them properly, because they are evenly divisible by 24. The NTSC standards for TV are set at 30 frames per second, so movies displayed over TV stations require the same adjustment techniques that won’t be perfectly smooth.
Buffers are a section of memory storage used to temporarily hold data as it transmits from one point to another, to ensure the data can be used without “skipping” if there is a temporary hiccup in the transmission of the data. Buffers are different from caches, which are usually used for data that will be read over and over, whereas a buffer usually operates on a first in, first out basis.
The light year is a measurement of length that equals the distance that light can travel in a vacuum over the course of one year–about 6 trillion miles or almost 10 trillion kilometers. Light years are generally used to measure distances to stars and galaxies, which should explain the reasoning behind the name of Toy Story’s Buzz Lightyear character.
Latency is an important measure of time delay in computer systems like networks and disk drives for how long the data takes to arrive. For instance, even if your network connection has a high total bandwidth, if there is a lot of latency it will be more difficult to play real-time computer games over the internet since each packet takes a while to transmit back and forth. The same thing is true of mechanical hard drives, which take longer to position the read head compared to solid state drives, which read directly from memory, making reading lots of small files much faster on an SSD.
The Turing test is a test of a computer’s ability to exhibit intelligent behavior, usually in the form of a natural language conversation between a judge, another person, and a computer designed to mimic a human. If the judge can’t tell the difference between the second person and the computer, it has passed the Turing test. In the hilarious TV cartoon Futurama, they joked of a reverse Turing test to figure out if a robot was really a robot.
Fuzzy logic is a form of logic processing that deals with values that aren’t exactly true or false, but might have values that range in degrees between the two. For instance, temperatures might be considered hot, cold, very hot, or very cold, but the exact temperature numbers might vary depending on the scenario or the person involved.
Data mining is a field of computer science usually used by large companies to discover patterns in large sets of data. This allows companies like Walmart to figure out that people usually buy certain items together, and place them next to each other in the store. Perhaps the most controversial example is when Target used data mining on their customer’s purchases to determine when women were pregnant, and started sending books of coupons to their door.
Optical character recognition is a computer technology that takes scanned images of pages containing handwriting or printed text and converts them to text that can be read by a computer and manipulated by word processing programs. Most scanners include the functionality in their provided scanning application, though the results are not always consistent.
Pretty Good Privacy (PGP) is a data encryption program that provides cryptographic privacy and authentication for sending data. It is often used for signing, encrypting and decrypting emails and files to increase the security of sending data over email.
A floating point number is a number with a set number of digits where the decimal point can be placed anywhere, as 10.5, 3.14, or -623.1231. This allows numbers of different precision to be stored in the same amount of data. Numbers which do not have decimal points are called integers. The computing of floating point numbers is very important for image processing and 3D video games, so the processors on video cards are specially designed to compute floating point numbers quickly.
BASIC, which stands for “Beginner’s All-purpose Symbolic Instruction Code”, is a programming language developed in the mid-1960s intended to provide computer students with a simple way to write programs. It eventually evolved into Microsoft’s Visual BASIC, an easy-to-use but fairly slow development environment that made creating new functionality easy for junior developers, though not performant. These days, Visual Basic .NET compiles into standard .NET Framework executables that are interchangeable with other languages.
Thunderbolt is a high-speed I/O technology developed by Intel and introduced by Apple Computer to enable high-speed data transfer between your computer and hard drives, monitors, and other accessories. It is based on PCI Express so external devices can operate as fast as internal components. Thunderbolt is capable of 10 Gbps of bi-directional throughput.
OpenGL or the Open Graphics Library is a 3D graphics language developers can use to create graphics and special effects that will appear uniform across any operating system using any hardware, which supports OpenGL. This makes it much easier for developers to port 3D games and programs to various platforms. OpenGL was created and developed by Silicon Graphics.
Grayware are annoying programs apart from malicious software such as viruses, Trojan horses. Grayware may include spyware, adware, dialers, joke programs, remote access tools, and other types of programs that don’t really damage your computer but slow things down, irritate you, and even worse: possibly steal your personal information.
A Dynamic Link Library is a file that contains a range of functions and other shared code that can be accessed by a Windows executable. In this way, the shared code can be easily updated by simply upgrading a single file, instead of every application having their own copy of the code. DLL files can be used by multiple programs and can even be accessed by several programs at the same time. DLL files usually end in .dll but can also use .exe, .drv, and .fon.
In older CRT monitors and TVs, magnetic charges would build up inside them causing a loss of color accuracy. To fix this problem, displays were equipped with a degauss function which, when used, would discharge this magnetism. Most sets would automatically degauss when they started up, which you would notice as a thunk or a hum when the set turned on. New flat-panel LCD monitors do not have a degauss function because magnetism does not build up in them.