Asymmetric Digital Subscriber Line (ADSL) A new technology that provides high transmission speeds for video and voice to homes over ordinary copper telephone wire. It will be most cost-effective in areas with a low market penetration of cable TV. Investopedia Says: Sometimes just called DSL, this is considered to be the major competition to cable modems. Related Terms: Bandwidth Broadband Internet Service Provider - ISP Very Small Aperture Terminal - VSAT |