An analog signal is an incessant signal for which, the time differing aspect of the signal is a depiction of some other time differing quantity. It varies from digital signals in terms of tiny, meaningful fluctuations in the signal. An analog signal utilizes some feature of the medium to communicate the signal's information. An aneroid barometer utilizes revolving position as the signal to communicate pressure information. In electrical terms, the feature that is most frequently utilized is voltage.
An analog signal has unlimited resolution. Practically, an analog signal is put through a finite slew rate and noise. Hence, both digital and analog systems are subject to confines in bandwidth and resolution. As analog systems turn more and more compound, effects like noise and non-linearity eventually corrupt analog resolution to such a degree that the digital systems’ performance may exceed it. Likewise, as digital systems turn more compound, errors may happen in the digital data stream. A digital system with similar performance is more composite and needs additional bandwidth as compared to an analog system with the same performance. In an analog system, it is hard to spot when such corruption takes place.
However, in a digital system, corruption can be spotted and corrected with comparative ease.
Advantages and disadvantages of analog signals:
The chief advantage of analog signals is the excellent definition which has the capacity for an unlimited amount of signal resolution. As compared to a digital signal, an analog signal is highly dense.
The main disadvantage of analog signals is that all systems involved have noise. Since the signal is replicated, or broadcasted over a long distance, this noise becomes dominant. In electrical terms, these losses can be reduced by defending, several types of cables such as twisted pair and good connections.