What are the connections on this German TV socket?
can you please explain to me what does each port in the socket does?


In your photo they are labelled DATA, TV, R

So it is reasonable to assume


Some kind of Internet connection.
A TV antenna.
A Radio antenna.


Nowadays the TV signal is likely to be DVB-T. The antenna and coaxial cable and connectors are the same as for the old analogue PAL signals. It is possible that it is DVB-S from a satellite dish. I'd ask the building manager (if there is one).