from
The Free On-line Dictionary of Computing (8 July 2008)
toolbar
<operating system> A common {graphical user interface}
component, consisting of a permanently visible row of button
{icons} that, when clicked with the {mouse}, cause the program
to perform some action such as printing the current document
or changing the {mode} of operation.
The toolbar buttons often invoke functions accessible via
{menus} but they are easier to use since they are permanently
visible. A typical use would be in a {paint} program where
the toolbar allows the users to select one of the various
painting "tools" - brush, pencil, bucket etc.
Some {application programs} under some {operating systems} may
allow the user to customise the functions accessible via
toolbars; in others, the choice is fixed by the programmer.
(2003-10-24)