Question

which key to move the cursor or page down by one screen​

Answer 1

I hope u will like. You can simply press Shift-right-arrow, and then start typing. In contrast, to these combination shift-arrow commands which move the cursor to the beginning and end of lines, the Ctrl-left-arrow and Ctrl-right-arrow keys move the screen image 20 spaces in the opposite direction to the arrow, without moving the cursor.