streams?

[ripley]

Hi, I'd like to describe a school but I don't know if the description is understandle and if I am using the right words because the description has to do with our school system

After elementary school students go to Scuola Media. It lasts three years.
When you start scuola media you are in the first form; the following year (if you are good) you are in the second and then in the third form.
Since there are a lot of students they are divided into different classrooms which are indicated by a number(1, 2 or 3 according to the school form and a letter of the alphabet)
If there are 40 students in the first year ; twenty of them will be in classroom 1 A and the others in classroom 1 B; if there are more they will be in classroom 1 C;
In Italian we call the different letters of the alphabet "Sezioni" litterally "Sections"; What is the English rightword for it? streams ? I am not sure at all;

How can I say that in a school there are four "sections" (that is 3 classrooms A (1,2,3), three classroom B (1,2,3)and three classrooms C(1,2,3)?
There are four classrooms for each school year? for each grade?
What about the meaning of the word streams? Does it correspond to sections?
Thanks Rip

[Tdol]

In British English, steaming refers to grouping students by ability.