Step 1: What is asked.
We need the planet seen just before sunrise or just after sunset.
Step 2: Inner planet idea.
Venus moves around the Sun closer than the Earth does. So from Earth, Venus always looks near the Sun in the sky.
Step 3: When it is seen.
Because it stays close to the Sun, we can spot it only at twilight, that is at dawn or dusk.
Step 4: Its nicknames.
When seen before sunrise it is called the Morning Star. When seen after sunset it is called the Evening Star.
Step 5: Why it stands out.
Venus is very bright, the brightest object in the night sky after the Moon, so it is easy to notice.
Step 6: Conclusion.
So the planet seen at twilight is Venus.
Answer: Venus