This Standard license allows for 2VMs on this host. In place of the licensed version (i.e. Server 2019) , you can run prior (older) versions or lower editions in any of the OSEs of the licensed server. If you have Windows Server 2019 Datacenter edition you will have the right to run the bits of any prior version or lower edition (Datacenter, Standard or Essentials). If you have Windows Server 2019 Standard edition, you will have the right to run the bits of any prior version of Standard or Essentials edition.

The WS2019 standard edition enables to run two OSEs. If you need more OSEs, you have to buy additional licenses.