Anchors are used to determine the vertical and horizontal positioning of a child object relative to its parent. The end of the anchor with a symbol on it is attached to the parent object.
Since the size of some layout objects may change when the report runs (and data is actually fetched), we need anchors to define where we want objects to appear relative to one another. An anchor defines the relative position of an object to the object to which it is anchored. Positioning is based on the size of the objects after the data has been fetched rather than on their size in the editor. It should also be noted that the position of the object in the Layout editor effects the final position in the report output. Any physical offset in the layout is incorporated into the percentage position specified in the Anchor property sheet.
It indicates that whether you want to keep a object and its entire contents on the same logical page. Setting its property to 'yes' if the object and its entire contents cannot fit in the page it will be moved to next logical page.