What is the difference between the Hot key and shortcut key

hotkey: which is used to open r close an application.....
shortcutkey: used to perform actions with in the application....

The shortcut keys are related to a specific window and will only work in that window. It is part of the name of a menu item or button, where it can be underlined, and is available (without modifiers) when that menu item or button is directly available.

A combination of key that the user can press to perform an action quickly is called as an hot key.