What does a digital oscilloscope primarily measure?

A digital oscilloscope is a specialized electronic instrument primarily used to measure and display voltage signals as they change over time. This capability allows it to visualize waveforms, making it an invaluable tool in electronics for analyzing signal behavior, such as determining amplitude, frequency, rise time, and other characteristics of various signals. By converting the analog signal into a digital form, it can store and process the information more effectively, allowing for detailed analysis.

While current frequency interactions, temperature fluctuations, and light intensity variations are important measurements in their respective fields, they do not align with the main function of a digital oscilloscope, which focuses on capturing and displaying voltage signals. This specificity makes the correct answer particularly relevant in the context of understanding digital instrumentation and its applications.