Internships & working experience

Hi,

I've a question about work experiences. I am an 11th grader at the moment, and I am preparing for unis.

The thing is, when I read other well written personal statements, they always have some work experiences related to their area of study. But the thing I don't understand is, they are really "working". meaning not an internship, but actually working in a company.

Does this mean that these personal statements are graduates wanting to do further studies, or do 12th graders actually work in a company??????

I personally want to study economics/business/management or something of this area, and if I want to get an internship or something, what should I do??