This is the 3289th most frequent Japanese word.
後で
"後で" means "later" or "afterwards."
Here, "後で" is used to indicate that the action (doing homework) will happen at a time following the present moment.
宿題は後でやります。
I will do my homework later.
In this sentence, "後で" denotes a planned activity (watching a movie) occurring in the future.
後で友達と映画を観る予定です。
I plan to watch a movie with a friend later.
"後で" implies that the discussion regarding the issue will take place at a subsequent time.