The Launcher is one of the main access points for applications in Unity interface. It provides quick access for launching applications and managing running applications. If your question is about creating or managing application launchers in Ubuntu, use the [.desktop] tag instead. For the Dock in Ubuntu 17.10 and later releases with GNOME 3, use [ubuntu-dock] tag.
The launcher is a user interface element designed to both provide quick access to frequently used applications, as well as display and group currently running applications.
The launcher sits at the left side of the screen in Unity desktop environment. The Unity Launcher is called the Dock in the default GNOME desktop environment in Ubuntu 17.10 and later.
The Dash icon is at the top, followed by icons for applications. In Ubuntu 17.10 and later the Dash icon has been replaced by the Show Applications icon at the bottom of the Dock.
Applications in the launcher have quick lists accessed by right-clicking on the icons. These can be customized and provide access to common tasks.
