ADSL is a type of high-speed Internet access for consumers. ADSL stands for Asymmetric Digital Subscriber Line. This is a technology that allows for digital transmission over existing telephone lines. The term 'asymmetric' refers to the fact that the speed that you send data can be different than the speed that you can receive data. Therefore, a typical user will have a faster download speed than upload speed through ADSL. ADSL service is typically many times faster than a 56k modem while allowing for regular phone/voice usage simultaneously on the same telephone line. ADSL service is an "always-on" type of connection, which is especially vulnerable to hacker attacks. Users can prevent unauthorized access with a software firewall product.