psql (13.1 (Debian 13.1-1.pgdg100+1), server 12.5 (Debian 12.5-1.pgdg100+1))

Dear, I'm new at postgresql and I've installed it on a Debian 10
(stable) server.

I don't know why, but after executing the psql command, I see this message:

psql (13.1 (Debian 13.1-1.pgdg100+1), server 12.5 (Debian 12.5-1.pgdg100+1))

It seems both the posqgresql 12 and 13 are installed at the same time...

I think I've installed postgresql 12, but here I see I have these
packages after upgrade with apt:

ii  postgresql                      13+223.pgdg100+1             all
       object-relational SQL database (supported version)
ii  postgresql-12                   12.5-1.pgdg100+1             amd64
       object-relational SQL database, version 12 server
ii  postgresql-13                   13.1-1.pgdg100+1             amd64
       object-relational SQL database, version 13 server
ii  postgresql-client-12            12.5-1.pgdg100+1             amd64
       front-end programs for PostgreSQL 12
ii  postgresql-client-13            13.1-1.pgdg100+1             amd64
       front-end programs for PostgreSQL 13
ii  postgresql-client-common        223.pgdg100+1                all
       manager for multiple PostgreSQL client versions
ii  postgresql-common               223.pgdg100+1                all
       PostgreSQL database-cluster manager

Is this correct or do I have to uninstall the postgresql 13 packages ?

Within psql CLI, the version is:

SELECT version();

 PostgreSQL 12.5 (Debian 12.5-1.pgdg100+1) on x86_64-pc-linux-gnu,
compiled by gcc (Debian 8.3.0-6) 8.3.0, 64-bit
(1 row)

Thanks a lot!!!