Simplify the following text for a Grade 9 native English-speaking person.
Original: Made of six to twelve sails covered in reed matting or cloth material , these windmills were used to grind grain or draw up water , and were quite different from the later European horizontal-axis versions .
Simplified: Made of six to twelve sails covered in reed matting or cloth , these windmills were used to grind corn or draw up water , they were quite different from the European versions .