Panel (computer software)
A panel is "a particular arrangement of information grouped together for presentation to users in a window or pop-up."[1] In ISPF, a panel is "a predefined display image that you see on a display screen.".[2]:p.16
A panel graphical control element is commonly packaged as part of a widget toolkit (libraries that contain a collection of graphical control elements) for a graphical user interface. See toolbar and dialog box.
Panels in widget toolkits
Panels in widget toolkits (libraries that contain a collection of graphical control elements) often have no specific graphic characteristics, but are mainly used to group child widgets together. They provide better control on the layout of the graphical control elements.
For example, in this XUL definition, two horizontal hbox panels are enclosed in a vertical vbox panel, alongside two buttons. This insures that the label and the textboxes for the Login and the Password fields are correctly aligned.
<vbox>
<hbox>
<label control="login" value="Login:"/>
<textbox id="login"/>
</hbox>
<hbox>
<label control="pass" value="Password:"/>
<textbox id="pass"/>
</hbox>
<button id="ok" label="OK"/>
<button id="cancel" label="Cancel"/>
</vbox>
