If you are teaching, you know this is the class for the student who doesn’t write as well. But what student is that?
It depends.
And it depends mostly on the college you teach at.
I have taught developmental writing where the students didn’t know grammar rules at all. They didn’t know that sentences started with capital letters and ended with periods.
And I have taught developmental writing where the only difference between those students and the regular freshman composition students is the speed with which the two groups can write. If the student needs time to think before they write, then they are in the developmental course.
I am not sure that developmental writing as it is often taught helps those students. They still have plenty of time to build up to their writing in developmental writing. And how much time will they have to build up to writing in other courses? I am not sure.
What developmental writing is depends a great deal on the school.