Which statement best describes digital signals?

• A. A string of 0s and 1s forming binary
• B. A continuous range of voltages
• C. Analog signals
• D. Variable resistance values

Answer: (A)

Digital signals are defined by discrete states that encode information. In most systems, those states are two levels, representing 0 and 1. So a digital signal is a sequence of binary values over time—essentially a string of 0s and 1s. This binary representation makes it robust to noise because each value is read against a defined boundary, not by a continuously varying value. By contrast, analog signals vary continuously across a range of voltages and don’t use fixed, separate levels. A changing resistance value describes a physical property that isn’t the standard way digital data are encoded.