Which of the following describes modulation?

Modulation is the process of altering a carrier signal to encode information for transmission. This involves changing specific properties of the carrier, such as its amplitude, frequency, or phase, to represent the data being sent. By modifying these characteristics, modulation enables effective communication over various media, ensuring that the information can be transmitted and received accurately.

For instance, amplitude modulation (AM) changes the amplitude of the carrier wave, while frequency modulation (FM) varies its frequency. This capability to alter the carrier signal’s properties is essential for efficient data transmission in both analog and digital formats, allowing signals to be transmitted over long distances while being less susceptible to interference.

The other options fail to accurately capture this definition. While magnifying signals or simplifying signal structures may pertain to signal processing, they do not define modulation. Similarly, the mention of data transmission without encryption does not relate directly to the modulation process, as modulation itself can occur with or without encryption. Thus, the chosen response is the most precise definition of modulation in the context of communications.