a long string of numbers
Voice signals are analog signals, whereas computer signals are digital .
Digital signal is moreefficientimmune to noiseerror freethan analog signal.
The electric motor does not work on the principle of the amplifier and the digital signals.
A digital converter converts the analog signals that are received by your TV to digital signals. Most TV providers only offer digital TV these days, so you only need it if you're still using analog.
AGND means Analog ground & DGND means Digital ground. Due to fast switching of digital signals it is possible for noise generation which affect nearby analog signals.(If common gnd used for both analog & digital). If separate gnd used for both the signals.Noise will not affect the signals.
Waves
Digital signals are measured in bits per second (bps).
digital signals have two values. 0 and 1.
Analogue signals are more vulnerable to error than digital signals. See the related question "Why digital signals are more noise free than analogue signals?" for more details.
modem is the device that carries digital signals
To measure time between digital signals.
Digital signals are measured in bits per second (bps).
Digital signals
it is an DAC (Digital to analogue converter
digital video camera
Analog signals require higher fidelity than digital signals because digital are either on or off while analog are continuous. A small difference in an analog signal is not detectable while it requires a large difference to turn on into off (digital signal). Error correction is easier with digital signals.
Hybrid signals are the combination of both analog and digital signals