Classifying Signals: Continuous vs. Discrete, Analog vs. Digital

Signals are fundamental to electrical engineering, serving as the carriers of information we process, transmit, and store. Understanding how to describe and categorize these signals is the first step in analyzing and designing complex electrical systems. Different types of signals require distinct mathematical tools and processing techniques. Correct classification is therefore essential for selecting the appropriate methods.

We can classify signals primarily based on their behavior along two axes: time and amplitude. The time axis determines whether the signal exists at every instant or only at specific points. The amplitude axis dictates whether the signal's value can take any value within a range or only a finite set of values.