Minimize an application window by single clicking on its icon on system taskbar or dock app launcher is a common used functionality.
By default, the minimise function isn’t enabled in Ubuntu Unity Desktop. So you cannot click on an app launcher icon to open an app and again click on it to minimise the app.
Some tutorial shows some lengthy procedures installing some applications.
I don’t like the default size of unity panel size. We can easily reduce or increase the icon size via the Appearance settings which can be opened from dash.
But as I am little crazy to do the things via terminal, after a bit googling, I found the solution as follows.
By default the unity will be showing Ubuntu Desktop as shown below.