A Hotkey (or accelerator key, shortcut key, keyboard shortcut, hot key, key binding, keybinding, key combo, etc.) is a key or set of keys that performs a predefined function. These functions can often be done via some other, more indirect mechanism, such as using a menu, typing a longer command, and/or using a pointing device. By reducing such sequences to a few keystrokes, this can often save the user time, hence "shortcut".
For shortcuts which consist of keys "pressed together", one usually first holds down the modifier key(s), then quickly presses and releases the regular (non-modifier) key, and finally releases the modifier key(s). This distinction is important, as trying to press all the keys simultaneously will frequently either miss some of the modifier keys, or cause unwanted auto-repeat. (en.wikipedia.org)
Store Manager for Magento has lots of hotkeys and they are changing all the time. So it's easier to understand how to find them than to learn all of them.
Store Manager has one basic Modifier key - Alt. All regular (non-modifier) keys you can find on the Main Menu drop-down names. Regular keys are underlined letters there.