DSL refers to a class of technology used to obtain more bandwidth over existing copper telephone cabling running between a customer's premises and a Telco's Central Office. DSL allows

DSL refers to a class of technology used to obtain more bandwidth over existing copper telephone cabling running between a customer's premises and a Telco's Central Office. DSL allows simultaneous voice and high-speed data services such as super-fast Internet access over a single pair of copper telephone wires.

DSL stands for Digital Subscriber Line. DSL uses the phone lines coming into your premises for landline phones, to connect to the Internet.  Your computers are connected to a phone line via a special DSL modem for the purpose of transmitting data.

The speed at which a DSL modem sends and receives data varies from hundreds of Kilo-bits per second to Megabits.