I. Theory
Like in English, German contains various ways to convey actions that occurred in the past. Das Perfekt, also known as the present perfect, is frequently used in day-to-day conversation. This tense corresponds to several past forms in English:| Ich habe gesagt. I said, I did say, I was saying, I have said. Du hast gearbeitet. You worked, you did work, you were working, you have worked. |
As you can see from the examples above, this tense can be used in various situations and carries a wider range of meaning than the various nuanced forms in English.