The OS X Dashboard is a collection of widgets within OS X that can be used for common tasks such as a calendar, calculator, an address book etc. By default, the Dashboard widgets can be accessed quickly by pressing F12 (function key and F12 key). Otherwise you can locate it in the Dock with the picture shown here.
Adding Dashboard Widgets
Once you click the Dashboard icon or F12, the Dashboard widgets are maximized on the screen and are superimposed over the rest of the programs.You will notice a sign “circled +” sign in the left bottom of your screen when the Dashboard is superimposed on your screen. This button is used to add widgets to Dashboard. Click this and a bar will appear at the bottom of the screen with all the available widgets. Also, the “circled +” which change to a cross or close button.
To make the widget active, drag and drop the particular widget to the Dashboard. You need to click the cross sign on the widget to remove it Dashboard.
Note that some of the widgets displayed require an active internet connection like the weather widget.
Adding Dashboard widgets can also be taken to the next step by utilizing the option to add dashboard widgets from Apple website. Apple encourages developers to create and publish their own widgets to maximize the user experience. There are tons of widgets available at Apple website and also, you can click here to get the Top 50 widgets. For example, my favorite one is silly widget Eyes 2: Homer Is Watching You 2.14 (Homer Simpson watches your every (mouse-)move on the Dashboard!)