Browser is the web browser application in the default Audrey image. It is also the name for the second button from the top on the right side of the screen. You cannot remap these buttons easily. Browser is a lightweight version of the Voyager web browser.
Changing the look of Browser[]
The browser Audrey uses is called Voyager. This browser uses gifs for its buttons. These gifs are located in /kojak/browser.images.
It's a little trickier to replace these. Each button has 2 or 3 graphics, and some of the buttons are different sizes. The smartest thing to do is to copy the files to your PC/Mac to get the graphic sizes then edit them as you like. Just make sure you use the exact same name as the file you replaced.
Another bit of info: In the directory /kojak is a file browser.dat. This file tells the browser where each button should be placed on the screen. I messed with this file once but not too much. I didn't want to mess anything up. Is uses coordinates like 20,0,0,330. Look into this if you are thinking of rearranging the buttons.