The DockSpawn library provides a web-based dock layout engine that aids in creating flexible user interfaces by enabling panels to be docked on the screen similar to Visual Studio IDE.

The library is based on "https://node-projects.github.io/dock-spawn-ts/".

There are a few key elements to this component:

1. Dock Host: The div/placeholder that will be hosting the dock manager (it placed in design time by developers)
2. Dock Manager: The div within the DockSpawn widget that facilitates the docking functionality thru the docking engine. 
3. Panel Containers: The individual divs/node representing the floatable content windows.
4. Panel Container tab: The individual Panel Containers are organized in a tabbed fashion in each of the dock locations. The Panel Container tabs are tab headers from the tab layout.
5. Dock Wheel: A virtual element that illustrates different dock positions while docking the panels
6. Dock Preview: A virtual element that gives a preview of the dock layout when a panel is moved over a dock located in the Dock Wheel.