In literature, what is a subject?

Literature is divided into 2 main groups-prose and poetry.

In prose you have to read books, stories and understand them so that you can interpret them using your own words.

In poetry, you have to read poems written by famous poets, and understand what message he's trying to transmit. In the past you had to learn poems by heart and then recite them to the teacher, But this style doesn't exist anymore.

It's like a theme or assesment. Such as poetry. You might study it for a while, and then move on to another subject. Example: I studied poetry for 3 weeks, then I moved on to ... blah blah blah. Get it?