Snap points are implied points in the model, for example, the center point of a sphere or end points of a pipe. You can toggle the rendering of snap point in the 3D model. You can also change the size of the drawn snap points by using the Options Editor.
Click the application button > Options.
In the Options Editor > Interface node, click the Display option.
On the Display page > Primitives area, enter a number between 1 and 9 in the Snap Size box.
This sets the size in pixels of snap points drawn in the Scene View.
Click OK.