Answer:
Present perfect tense is related to the present in some way, while past simple tense happened at a specific time in the past and is a finished action.
Step-by-step explanation:
Present perfect tense describes something that happened in the past, but that is related to something in the present (example: I have read 5 books by Ernest Hemingway).
Past simple tense is used for things that happened at a definite time in the past (example: I met my friend when I was seventeen).