While running your Macintosh if you look at the dock you will be unable to tell which of the application icons are hidden. But if you are smart enough and run a quick command from the terminal then you can make the invisible icons to appear as translucent so that you can view them with ease.
If you are a Mac user who uses multipurpose work at once then the feature that enables to hide the windows of the application that are currently working is excellent for you. To hide all the application windows that are currently working you will have to click cmd+H. All the application windows that are currently working will disappear and then later you will find that they are running in the background. If you wish to revive the application windows again then all you have to do is to click on the icon and the windows that have been hidden will pop up.
On the other hand you can also close all the other applications that are not currently running. For example by clicking Cmd+Option+H all the other applications apart from running shall be closed and you will find that they are gone for good. This will allow you to focus on the task that you are currently doing.
But there is one disadvantage in this method. You cannot tell which applications are hidden and which are not. For example after you had hidden an application, it will look the same as the previous one and therefore it is hard for you to find the one that has been hidden. Through a change in settings you can easily tell which application is hidden and which is not by making the hidden application to appear as translucent.
Here is how to do it
After launching there terminal application enter the following command
defaults write com.apple.Dockshowhidden -bool YES
After you have hit enter, type this command so that the changes can take place
killall Dock
Again hit enter and you are done. You have just made the hidden applications to turn translucent