oooh 
i take it this is a europe thing? will still read 
Particularly a UK thing! It’s one of the 3 or 4 routes you can take to qualify as a teacher
I’ll read through it once I have time, but I just wanted to comment that in the US you go through college or University for like four years (this is for every major), and depending on the school if you’re gonna be teaching high schoolers it’s basically like you’re majoring in your subject area and Secondary Education.
You do that for most of college, then eventually you need to complete I think a certain hours student teaching which takes up a whole semester. You have a mentor teacher who helps you and stuff. Before that you’ll also sit in on some classes, and in some schools in different areas to see where you might fit best.
Then after you do all that you get your certification (I believe, haven’t done it yet lol).
It depends I think on a lot of things and varies state by state but this is our process for it here.