Question: is tahajjud and witr the same?
Answer: Witr is the last prayer in the day. Depending on the school of thought, it can be 1 rakat and prayed after isha/before you sleep. Tahajjud is when you sleep after isha, wake up in the middle of the night to do sets of voluntary salah. An example would be you wake up at 2 AM and then pray 6 sets of 2 rakat salahs.