answer:
When you re-open a document that you have already been working on, the scroll bar on the right-hand side allows you to navigate through the content of the document vertically. The scroll bar is a user interface element that provides a visual representation of the length of the document and your current position within it.
By interacting with the scroll bar, you can perform the following actions:
Scroll down: Dragging the scroll bar handle or clicking the down arrow allows you to move down the document, revealing content that was not visible on the screen.
Scroll up: Similarly, dragging the scroll bar handle upwards or clicking the up arrow lets you navigate to the previous content in the document.
Jump to a specific location: Clicking on any area of the scroll bar (except the arrows) will jump the document to the corresponding position. This allows you to quickly move to a specific section of the document without having to scroll manually.
Scroll with the mouse wheel: If you have a mouse with a scroll wheel, you can use it to scroll up or down in the document. Scrolling the wheel away from you will move the content up, and scrolling it towards you will move the content down.
Keyboard shortcuts: Many applications and operating systems support keyboard shortcuts for scrolling, such as pressing the arrow keys or using page up/down keys.