Kroger offers jobs to 14-year-old candidates who have valid work permits. Some positions at Kroger do require workers to be older, however. For example, a person must be at least 18 to work as a butcher or to have a job that requires handling tobacco.
The main difference when it comes to nurse practitioner vs physician assistant schooling is that there are a more limited number of accredited schools for physician assistants in the US, currently a little over 160, compared to schools for nurse practitioners which there are over 800.
Doctor vs Nurse. There has always been a huge difference between a nurse and a doctor. As you might have witnessed yourself, a doctor is the one who does the operations while the nurse is the one who assists him. Hence, what might really be the difference is what they have studied, which is why they reached such professions.