Trigonometric Functions: These include sine (sin), cosine (cos), tangent (tan), and others. They relate angles and sides in right triangles.
Periodic Function: A periodic function repeats its pattern indefinitely over regular intervals. $\sin(t)$ is an example of such a function because it keeps oscillating repeatedly.
Amplitude: In relation to $\sin(t)$, amplitude refers to half of the difference between its maximum and minimum values, which determines how high or low it reaches.