A deployment pool is a collection of one or more vApp templates and is specific to a single tenant.
Note the following regarding the relationship between labs and deployment pools:
When you create a lab, you must select an existing deployment pool to associate with that lab.
A deployment pool includes virtual machine metadata. The metadata primarily concerns the username, password, notes and a flag for each virtual machine within the vApp(s) associated to the deployment pool.
Any lab that does not override the virtual machine metadata values in its associated deployment pool gets those values.
A deployment pool is automatically created for a vApp built by Lab Builder.