Adding something to the Dock
Adding Something To The Dock
"The Dock" is the row of icons usually at the bottom of the screen, that looks like this (yours will have some different icons):
Occasionally, something will inadvertently get removed from the Dock, or you might install something new and you want to add it to the Dock. Here's how. (Thanks to Alida Ciampa)
Click on the Finder icon in your Dock to get access to your Applications folder.
Click on your Applications folder to view all of the apps on your computer.
Scroll down through the list of applications until you find the thing you want to add back (e.g., Firefox).
Drag the Firefox icon into your Dock. The other items in your Dock will part like the Red Sea, making room for Firefox. You can drop it any place in your Dock. Here's a very short video showing that step: