Broadband in telecommunications refers to a signaling method that includes or handles a relatively wide range (or band) of frequencies, which may be divided into channels or frequency bins. Broadband is always a relative term, understood according to its context. The wider the bandwidth, the greater the information-carrying capacity. In radio, for example, a very narrow-band signal will carry Morse code; a broader band will carry speech; a still broader band is required to carry music without losing the high audio frequencies required for realistic sound reproduction. A television antenna described as "normal" may be capable of receiving a certain range of channels; one described as "broadband" will receive more channels. In data communications an analog modem will transmit a bandwidth of 56 kilobits per seconds (kbit/s) over a telephone line; over the same telephone line a bandwidth of several megabits per second can be handled by ADSL, which is described as broadband (relative to a modem over a telephone line, although much less than can be achieved over a fiber optic circuit).
DSL-->DSL or xDSL is a family of technologies that provides digital data transmission over the wires of a local telephone network. DSL originally stood for digital subscriber loop, but as of 2009[update] the term digital subscriber line has been widely adopted as a more marketing-friendly term for Asymmetric Digital Subscriber Line (ADSL), the most popular version of consumer-ready DSL. DSL can be used at the same time and on the same telephone line with regular telephone, as it uses high frequency bands, while regular telephone uses low frequency.
The download speed of consumer DSL services typically ranges from 384 kilobits per second (kbps) to 20 megabits per second (Mbps), depending on DSL technology, line conditions and service-level implementation. Typically, upload speed is lower than download speed for ADSL and equal to download speed for the rarer Symmetric Digital Subscriber Line (SDSL).
For more information http://windows7.iyogi.net/
