What is the difference between ampicillin and amoxicillin?

what is the difference between ampicillin and amoxicillin?

I am not absolutely sure but I think they are basically the same drug. I believe they are an alternative to penicillin. Correct me if I a wrong?

the differences are rgarding to the time of adminstration ,Ampicillin given 4 times per day and Amoxicillin 3 times so Amoxicillin is better and quicker absorbed