Signal modulation is the process of altering a specific characteristic of a high-frequency carrier wave to encode information onto it. This technique is fundamental to wireless communication, enabling the transmission of data over electromagnetic waves. The three primary methods of modulation involve varying the signal's amplitude, frequency, or phase relative to the original carrier wave. By mapping different types of information onto these varied physical properties, complex digital and analog data streams can be efficiently transmitted across vast distances. This principle allows receiving devices to accurately decode the information by analyzing the controlled changes in the carrier wave's characteristics.