In the default setting, the Dock lies at the bottom of the screen, and contains 18 applications, a folder and the trash can. In this state, icons are clear and bubble numbers are easy to read. However, this default placement robs the user of vertical screen height, which is the axis that the user has least of. On a large iMac screen, the Dock can get away with living at the bottom, but consider the laptop user; space for them really is at a premium, and so it doesn’t make sense for the Dock to live at the bottom of the screen. This lack of vertical space is compounded by the various toolbars that applications have, almost all of which are displayed as an extra horizontal bar across the top of the application.
By default, on laptops, the Dock should be attached to either the left- or right-hand side of the screen.
OS X El Capitan 10.11.6.