Discovery Services allow OPC UA Applications to learn about other OPC UA Applications in a system and the necessary details on how to connect to them.

OPC UA defines three levels of dedicated Discovery Servers:

1. Local Discover Server (LDS)
2. Local Discovery Server with multicast extension (LDS-ME)
3. Global Discovery Server (GDS)

OPC 10000-12 describes how to use the Discovery services with dedicated Discovery Servers.