The term 'dsl' is likely a typo or an abbreviation. One common interpretation is "DSL," which stands for Digital Subscriber Line. It's a technology used to transmit digital data over telephone lines, primarily for internet access. DSL allows for high-speed internet connections while still using the same lines that carry voice calls.
The term "Digital Subscriber Line" derives from the combination of "digital," which means relating to data in binary form, and "subscriber line," referring to the physical telephone line used to connect a customer's home or office to the service provider. The technology was developed in the late 1980s to provide higher bandwidth than traditional analog modems.