The Option key (often labelled Alt) is found in the middle of the three keys either side of the Space bar; the three keys being from the outside moving towards the Space bar:
Control (ctrl), Option (alt) and Command (cmd)
The mod key, or alt key is called the option key on a Mac. It is to the right or left of the command key.
The option key is a modifier key (ALT) present on Apple Keyboard
Hold down the option (alt) key and press the 's' key.
Alt key or Option on Mac.
On a Mac keyboard, press and hold the option key, then type the number 3. Then release the option key. I don't know about on a Windows keyboard
Command-Option-Shift-T is the Mac version of the Windows command Control-Alt-Shift-T. In general the Mac uses the Command key where Windows uses the Control key.
±(on Windows® character map as Keystroke: Alt+0177)On a Mac, press and hold the option key, then shift and +Release the option key.
On a PC keyboard, the equivalent of the Mac's Option key is typically the "Alt" key. It is usually located on either side of the spacebar. Some keyboards may also have a key labeled "AltGr" which serves a similar function for accessing additional characters.
To turn off the negative effect on your Mac Book Pro (turning the screen black, white, and a few other colors), hold the command key, the alt/option key, and the ctrl key (all three in a row), and then hit the 8 key (the key above the keyboard, not on the number key pad).
You hold down the option key or alt, and click zero, you will then get yourself a degrees symbol like this: º
The same command on a mac would be command key(cmd)+A any ctrl key command is the same as the cmd key on a mac
Holding down the option key while starting up a Mac running Mac OS X enters the Startup Manager which will let you select where you want to boot from.