Digital lines refer to the representation of data in a binary format, using discrete values such as 0s and 1s. These lines are fundamental in digital communication, where information is transmitted over various mediums, including the internet and telecommunications. Digital lines ensure that data remains accurate and can be easily processed by computers and other digital devices. In the context of digital signal processing, digital lines can be visualized as waveforms that represent the flow of information. They are essential in technologies like fiber optics and wireless communication, enabling efficient data transfer and enhancing the performance of electronic devices.