2. Understand the importance of the sampling rate

If you are given a sequence of point sampling from a continuous-time signal, but I didn't tell you the information about the sampling rate, what will happen?

You can not recover the original signal, because you do not not you sample every second, or sample every day, or every month.

The sampling rate describes the repetition of sampling points, how many points do you have in one second. The sampling interval is easier to understand, it is the time interval between two sampling points, and the reciprocal of the sampling rate.