The input signal is an essential aspect of any electrical or electronic system, and there are several synonyms that can be used to refer to it. For example, the term "input voltage" is commonly used to describe the amount of voltage that is fed into a device or system. "Input current" is another synonym that refers to the amount of electrical current that flows into a system. "Input data" is a term that is often used in computer science and data analysis to refer to the information that is entered into a program or system. Other synonyms for input signal include "input waveform," "input pulse," and "input frequency." Ultimately, the specific synonym used will depend on the context in which the input signal is being discussed.