Which service is characterized by providing high-speed Internet access over existing telephone lines?

DSL, or Digital Subscriber Line, is characterized by providing high-speed Internet access over existing telephone lines. This technology utilizes the unused frequency on the telephone lines, allowing for data transmission to occur alongside voice calls. DSL can offer much faster speeds compared to traditional dial-up connections, making it a widely used service for residential and small business Internet access.

The underlying advantage of DSL is its ability to work with existing infrastructure, allowing users to maintain their traditional phone service without interference while accessing the internet simultaneously. This makes it a cost-effective solution for many users, especially in areas where newer technologies, like fiber optics, may not be deployed.

In contrast, fiber optic services require entirely new infrastructure with light-based technology capable of delivering extremely high speeds. Cable Internet uses coaxial cables, which are different from traditional telephone lines, and typically requires a cable service subscription. Satellite Internet also does not utilize telephone lines and is impacted by latency due to its reliance on satellites in orbit, making it less favorable for high-speed applications.