What is Replication slots in PostgreSQL Streaming

What is Replication slots in PostgreSQL Streaming replication slot postgres postgresql_slot module replication slot Replication slots are a persistent data structure used to track the progress of replication across subscribers, and to ensure that WAL data

replication slot In the context of logical replication, a slot represents a stream of changes that can be replayed to a client in the order they were made on the origin server

replication slot does not exist Replication Slots · the oldest WAL required by the consumer of the slot Replication Slot