1.
If you go back to a task or activity, you start doing it again after you have stopped doing it for a period of time.
I now look forward to going back to work as soon as possible...
Amy went back to studying.
PHRASAL VERB : V P P n / -ing , V P P n / -ing
2.
If you go back to a particular point in a lecture, discussion, or book, you start to discuss it.
Let me just go back to the point I was making.
PHRASAL VERB : V P P n