According to Microsoft, pressing the scroll lock key alters the behavior of the arrow keys and the page up and page down keys. It enables users to scroll through documents without changing the position of the cursor or selection.
The scroll lock key only works in a few computer programs, such as Excel 2010. In this program, when scroll lock is off, pressing the arrow keys moves the selection between cells. However, when scroll lock is on, pressing the arrow keys scrolls the spreadsheet either one row up, one row down, one column to the left or one column to the right. Some keyboards have a light that indicates whether scroll lock is on.