When an object is selected in visual studio, and a heavier border appear on the outer edges of the object.

Size Handlers

Explanation:

In Visual Studio, the fields, images, text boxes are considered as objects. Editing reports and applying same changes on the objects require objects to be selected. When a object is selected (by clicking on it), a frame appears around it along with squares. These squares are called size handlers. They allow users to change the size of an object. Object can be make longer, wider, smaller by using size handlers. Hence sizing handle is a tool used for resizing an object.