Okay, so Drang Nach Osten literally means "Drive to the East" in German. It was a policy adopted by some German states in the 19th and 20th centuries to expand their territory eastward into areas like Poland and Russia.
Think of it like a game of king of the hill, but instead of a hill, it's about getting more land. The countries to the west of Poland and Russia wanted more land, so they started trying to take it from the people living there.
Now, this idea wasn't new - countries have been trying to expand their land for as long as there have been countries! But it became more popular in Germany during the 19th century when they were trying to unite all the different German-speaking states into one country.
The idea was that if they could gain more land to the east, they could take over more resources, have more land for their people to live on, and create a bigger and more powerful German Empire.
However, this policy led to a lot of conflict and war. The people living in the areas being taken over didn't like it very much and fought back. Eventually, the policy fell out of favor and Germany ended up losing a lot of the land they had gained.
So, to sum it up - Drang Nach Osten was a policy where some German states tried to get more land to the east. They wanted more land and resources and a bigger empire. But it led to a lot of conflict and didn't work out very well in the end.