What does PGDG mean, in the Postgres YUM repositories?

What does PGDG mean, in the Postgres YUM repositories? pgdg slot Publication slots configuration involves using the Create Replication Slot command in PostgreSQL to establish a slot dedicated to publishing data This command slot24h MBBS, DNB , PGDG , FGID Morning Slots 03:00 AM 03:10 AM 03:20 AM 03:30 AM 03:40 AM 03:50 AM 04

ufa pg slot club pubreposapt jessie-pgdg main And then import sign key slot: FAILED (replication slot 'barman' doesn't exist Please execute