By default, Apple populates your Mac’s Dock with all sorts of apps and arranges them in a particular order. But there’s no rhyme or reason to the defaults, and you shouldn’t be afraid to add, remove, and rearrange apps on your Dock to your liking. The icons are there for you, so if they don’t meet your needs then change them! To add an app, drag its icon from the Applications folder in Finder to the desired spot on the Dock. To remove an app you never use, drag its icon far enough off the Dock that a Remove tag appears above the icon and then let go. To arrange the Dock icons in the order that makes the most sense to you, just drag each icon to your preferred location. I generally like to put my most-used apps in the left-most or top-most spots.