Scroll bars are control elements of the graphical user interface( GUI). They are located at the right and bottom edge of the window and are used to move displays that are larger than the window area vertically and horizontally.
Both scrollbars have scroll arrows at both ends to scroll the display vertically and horizontally. On each scroll bar there are sliders with which the screen display can be moved up and down or to the right and left, so that image contents that are outside the display area can be moved onto it. The size of the sliders depends on the size of the displayed document. A large slider indicates that the document is small, consisting of only one or a few pages. It is different with a small slider. The smaller the slider is, the larger the document is, which may well consist of hundreds of pages. The slider can be moved with the computer mouse.
Scrolling of the display is done with the scroll arrows. There are application programs that have fields with double arrows in addition to the scroll arrows. With these double field arrows the representation can be shifted page by page.