There are four types of bone binding for points in a vector layer that is nested inside a bone layer.
Binds an entire layer to a bone. You can do this by going to a child vector layer of the bone layer and use the Bind Layer tool to select the bone this layer should be bound to.
To release the layer, click outside any bones with the Bind Layer tool, or use the Release layer option from the Bone menu. If you release a layer, the bone binding reverts to the state that was in place before layer binding. So, in effect, layer binding just takes precedence over the binding state of each and every point in a layer.
Binds individual points to a bone. You can do this by going to a child vector layer of the bone layer and use the Select Bone tool to select the bone you want to use. Next, use the Bind Points tool to select the points, and either press the spacebar, or click the "Bind Points" button in the top part of the main window. You can also select a bone in any bone tool by holding the Alt (Option) key and clicking on a bone.
To release points, select the bone, which will light up the selected points, deselect the points you want to release, press press the spacebar or click the "Bind Points" button.
This uses bone strength to determine which points are bound.
You really should use region binding for more precise control. Flexible binding has a wider range, and the bone strength is more widely applicable. The type of flexi-point binding can be set in the Bone tab of the bone layer properties (double click on the layer in the Layers window, or select the layer in the Layers window and press the "..." button).
The default state of a layer is that all points are flexi-bound, but you can set individual points to be flexi-bound to a bone by selecting the bone (by Alt-clicking on it), next selecting the points you want to be flexi-bound, and select the Flexi-bind point option in the Bone menu. You can also flexi-bind all points in a layer, by selecting the Flexi-bind layer option in the Bone menu.
Points that have no binding, are called released points and are not affected by bone actions (translate, rotate, scale, IK-lock). You can release selected points through the Bone menu (Release point), or by first binding a point to a bone, and then releasing it by the method described in the point binding paragraph, above.
I hope this little overview will help you in your study of bones.