The hamburger button (also known as menu button, options button, and less frequently as hotdog button or pancake button) is a button typically placed in the top left or top right of a graphical user interface. It carries an icon consisting of three parallel horizontal lines (displayed as ☰), alluding to a list, and is named for its resemblance to the layers in hamburgers, hotdogs, or pancakes.
Selecting (tapping or clicking) this button results in a menu being revealed (sliding out or popping up), which distinguishes it from a menu bar, which is always on display.
Use of this icon as a graphical shortcut originated in order to save space on smaller devices (like smartphones).
On some platforms, to save even more space, the wider hamburger button has now been reduced to three vertically stacked dots (displayed as a tri-colon or vertical ellipsis ⋮ ).
Hamburger buttons have been criticized by TechCrunch as a "poor design choice" in apps for mobile devices.
The icon was originally designed by Norm Cox as part of the user interface for the Xerox Star, and it saw a resurgence starting in 2009 stemming from the limited screen area available to mobile apps.