If you have ever wanted to restore your OSX dock back to default app/icon layout you can now do it by running a 2 commands in your terminal. (No option to do this in your system preferences pane)
Step 1: Open terminal and copy and paste this command and hit return:
defaults delete com.apple.dock
Step 2: Copy and paste this command and hit return:
Your dock will restart and you will see the factory default icon/app dock. If you have deleted any stock apps, they may show as question marks. Enjoy!