A digital signal is a signal that is being used to represent data as a sequence of discrete values; at any given time it can only take on one of a finite number of values.[1][2][3] This contrasts with an analog signal, which represents continuous values; at any given time it represents a real number within a continuous range of values.
Answer: Maintenance. This is the stage where software is updated and hardware issues are fixed if and when they occur. Retirement. In this final stage, hardware becomes unusable or no longer needed and it needs to be properly removed from the fleet
