ADSL, or Asymmetric Digital Subscriber Line, is a technology that allows high-speed internet access over traditional telephone lines. It works by splitting the phone line into two channels: one for voice calls and the other for internet data. This means you can use the internet and make phone calls at the same time without interference. One of the key features of ADSL is its asymmetry, which means that the download speed is faster than the upload speed. This is ideal for most users who typically download more data, such as streaming videos or browsing websites, than they upload.