Usage & Type 
The flow layout is an invisible control used to combine other controls one after another. It can be inserted into every container control.
Example of the usage of flow layout
The controls within a flow layout
The controls will wrap to fit the size of its container (in this case a group).
Use the flow layout if you do not need to align controls with other elements in your interface. Controls that are added to the flow layout are able to wrap if the available space for displaying all controls in one line does not suffice.
To separate controls within the flow layout you should currently use a Text View control containing a simple space character.
When use the Flow Layout - When Use the Form Layout
Use the flow layout if you do not need to align controls with other elements in your interface; this will enhance performance because the flow layout does not have an overhead of table structures in the rendering
Use the form layout to align controls with respect to other controls in the user interface