What Is Streamlining?

Streamlining means to cut down on unnecessary things. To streamline a grocery list means to take off all unnecessary things and stick with the basics.
Some people use it when referring to weight loss. "She is getting streamlined."

The largest force is air resistance.
This is friction caused by the moving object pushing the air out of its way.
Air resistance can be reduced by changing the shape of the object
so that it can push the air away more easily.
This is called streamlining.

No I want to know what does streamlining means in the context of writing.