panel is container for group of controls like groupbox. But 
only difference is for panel no caption whereas groupbox 
contains caption property. By using this we can give one 
collective name for group of controls.

Both panel and groupbox acts like a container to other 
controls they help us a lot in  some applications where we 
want a group of controls or objects should be disabled or 
enabled when a specific task is performed

the main difference is 

group box has a hording where u can place a text of ure own

whereas a panel is just like a frame what we used in VB but 
has a scrollbar(hs,vs)

we are use to group box and panel same purpose but some 
lite differences are there group box can place the text but 
panel has scroolbars.