This piece is very simple. The ternary form is as straightforward as they come... The first A section is expository - it exposes the only melody of the piece.
The B section is developmental - it presents the motivic material of the A section in a varied form - instead of a minor, pretty much the same melody is playd in F major.
The second A section has a terminative function, and not just because it is the last section. In addition to finishing the music, it "confirms and reinforces an established key" - it's back in a minor, as was the first section.