What is the difference between the perfect and the pluperfect tense?

The pluperfect tense would be used to describe something that had happened or had been true at a point in the past, for examples, 'I had arrived early', 'I had forgotten to do my homework'.
The perfect tense would be used to describe the past, in particular, actions that took place in the past and were completed, for example, 'I have finished my homework', 'I gave them my phone number'.