The deal with internships, apprenticeships and learnerships

Hi. I have a bunch of questions and things I want to discuss about internships and apprenticeships. And learnerships, which I just recently discovered as of the time of the posting of this.

Firstly, what is the difference between the three?

I know that internships and apprenticeships have to do with gaining job and/or work experience.

What is a learnership? I do not know what that is. I assume this has to do with gaining job and/or work experience.

When I was in art school majoring in animation I never considered doing an internship. At the time I didn't really see the value in it and I didn't really have the time for it. I was young and ignorant.

Do you have to be a student to do an internship or an apprenticeship or a learnership? Is there an age limit to doing any of these?

Is doing any of them really worth it?

Besides internships, apprenticeships and presumably learnerships, what other means are there to gain job/and or work experience, and what are they called? Do you have to be a student for these means also, and is there an age limit for them?

Please help- thank you.