What are period, amplitude, and frequency?
Period is the time it takes for a resonant system to complete one cycle of its motion. For example, if a pendulum takes two seconds to swing over and back, then its period is two seconds. Amplitude is the maximum amount of motion a resonant system undergoes as it oscillates or vibrates (same thing). For example, if the pendulum swings one meter to the left of center and then one meter to the right of center, its amplitude of motion is one meter. Frequency is the number of cycles a resonant system completes in a certain amount of time. For example, if a pendulum swings over and back twice each second, then its frequency is two cycles-per-second or 2 hertz or 2 Hz.