ADSL

ADSL Definition Stands for "Asymmetric Digital Subscriber Line." ADSL is a type of DSL, which is a method of transferring data over copper telephone lines. While symmetrical DSL (SDSL) uploads and downloads data at the same speed, ADSL has different maximum data transfer rates for uploading and downloading data. For example, an ADSL connection may allow download rates of 1.5Mbps, while upload speeds may only reach 256Kbps. Since most users download much more data than they upload, this d...
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Contention Definition

Contention Definition (1) Contention means competition for resources. The term is used especially in networks to describe the situation where two or more nodes attempt to transmit a message across the same wire at the same time. (2) A type of network protocol that allows nodes to contend for network access. That is, two or more nodes may try to send messages across the network simultaneously. The contention protocol defines what happens when this occurs. The most widely used contention pro...
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Channel Definition

Channel Definition (1) A transmission path . (2) A set of properties that distinguishes one channel from another. For example, TV channels refer to particular frequencies at which radio waves are transmitted. IRC channels refer to specific discussions. (3) In sales and marketing, the way in which a vendor communicates with and sells products to consumers. (4) In a field-effect transistor, such as a MOSFE T, a channel is the semiconductor path on which current flows. (5) For IBM PS...
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CSMA/CD – Carrier Sense Multiple Access / Collision Detection

CSMA/CD - Carrier Sense Multiple Access / Collision Detection Short for Carrier Sense Multiple Access / Collision Detection, a set of rules determining how network devices respond when two devices attempt to use a data channel simultaneously (called a collision). Standard Ethernet networks use CSMA/CD to physically monitor the traffic on the line at participating stations. If no transmission is taking place at the time, the particular station can transmit. If two stations attempt to transmi...
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Lossy Definition

Lossy Definition Lossy file compression results in lost data and quality from the original version. Lossy compression is typically associated with image files, such as JPEGs, but can also be used for audio files, like MP3s or AAC files. The "lossyness" of an image file may show up as jagged edges or pixelated areas. In audio files, the lossyness may produce a watery sound or reduce the dynamic range of the audio. Because lossy compression removes data from the original file, the resultin...
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Lossless Definition

Lossless Definition Lossless compression reduces a file's size with no loss of quality. This seemingly magical method of reducing file sizes can be applied to both image and audio files. While JPEGs and MP3s use lossy compression, newer compression algorithms, such as JPEG 2000 and Apple Lossless compression, can be used to create lossless compressed files. Lossless compression basically rewrites the data of the original file in a more efficient way. However, because no quality is lost, ...
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Codec Definition

Codec Definition Codec is short for "coder-decoder." It is an algorithm used to encode data, such as an audio or video clip. The encoded data must be decoded when played back. A media codec is not equivalent to media compression, since it is possible to encode a file without compressing it. However, most codecs do compress the original data, reducing the size of the original file. This is important for multimedia files, since they often have large file sizes. Compressed files take up les...
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Virtual Reality Definition

Virtual Reality Definition While the word "virtual" is typically overused in the computer world, it is aptly placed in the phrase "virtual reality." According to the American Heritage Dictionary, virtual means "existing or resulting in essence or effect though not in actual fact, form, or name." It can also mean "created, simulated, or carried on by means of a computer or computer network." Therefore, virtual reality is best described as an illusion of reality created by a computer system. A...
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iCloud Definition

iCloud Definition iCloud is an online service provided by Apple. It provides an email account, online storage, and backup services. It also allows you to share data between devices, such as Macs, iPhones, and iPads. Below is a list of features included with iCloud: Mail – an email account that can be automatically configured on Apple devices and accessed via Apple's webmail interface; iCloud email addresses end with mac.com, me.com, or icloud.com. Contacts – your address book is stor...
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Yosemite Definition

Yosemite Definition Yosemite is the name of Apple's eleventh version of OS X, released on October 16, 2014. It follows Mavericks (OS X 10.9) and is also called OS X 10.10. While it is normal for each new version of OS X to include slight modifications to the user interface, Yosemite presented the most drastic change in several years. The interface includes many translucent elements, in which objects are semi-transparent. It includes a more "flat" design than earlier versions of OS X with new...
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