A T1 line is a type of digital transmission line that can carry data at a speed of 1.544 megabits per second (Mbps). It is commonly used for internet and telephone services, providing a dedicated connection that is reliable and consistent. T1 lines can support multiple channels, allowing for simultaneous voice and data transmission. These lines are often used by businesses that require a stable and high-speed connection for their operations. Unlike traditional phone lines, a T1 line can handle a larger volume of calls and data, making it an ideal choice for organizations with significant communication needs.