x Audio Analog Phono Connection/s

Line level is the signal level outputted by virtually all domestic audio equipment, usual around 2V it's analogue and so can degrade over distance.
Usually a line level signal is connected between equipment using RCA phono connections with white and red (White for left, Red for White) connectors for a stereo signal, the sockets are pictured above
Any equipment you see with these connections is usually outputting or inputting a line level signal, except turntables which output at phono level