On the Mac keyboard, it is the key to the side (left or right) of the Spacebar with an Apple logo and a "⌘" symbol that is known as Saint John's Arms, or a Bowen Knot; it looks like a flower. The Apple key, Apple button, or what is also known as the Command Key, is a key that adds function; usually with the combination of another key being pressed. IE: Apple+C is a "copy" command, Apple+V is a "paste" command, Apple+Shift+3 with take a picture of your computer screen and save it as an image.
Early Apple computers had an Apple on the Command (cmd) key which was also known as the Apple key. This was abandoned with the Macintosh as the Apple symbol, denoting the shortcut keys, was filling the menus which was seen as over usage of their logo. Susan Kare found the Saint John's Arms symbol which was used to replace the Apple on the Command key.
Unfortunately, you will probably need to be more specific. I've never heard of a Mac having a "default button," and I'm typing on one right now. Look up the model of your computer on Apple's support site, and their should be diagrams and other documentation that should suit your needs.
Many refer the Cmd-button to the Apple-button since it used to have the Apple-logo on it. The Cmd-button is placed to the right and left of the space bar.
next to the space bar
The keyboard shortcut for adding a bookmark in Safari or Firefox is Command (⌘) - D.
command - v
ctrl+i is the keyboard shortcut of the Italic button.
alt 4
Command A = Select All
the on button
One can purchase a Mac keyboard wherever Mac computers and accessories are sold. The best place to purchase a Mac keyboard is directly from an Apple retail store, or the Apple Online Store.
Apple has a page about the Mac keyboard that includes several images. (See links below)
The mac shortcuts are the same as the Microsoft shortcuts, except you use the "command" button instead of the "control" button.
On a keyboard the times button has the symbol "*" printed on it, this is usually found as upper case "8" but there may also be a "*" present on the numeric keypad section of your keyboard, if your keyboard has this.
the command button
it is not a code! all it is on a mac is a keyboard shortcut (not a mac user sorry about now knowing it) and on windows or Linux etcetc is unsure. look it up: windows or mac keyboard shortcuts or hotkeys