Database is a software, so upon installation I will have installation location and database files location. To check the locations issue the following command.

[postgres@postgreshelp  ~]$ ps -ef|  grep postgres
postgres  4270     1  0 Mar03 ?     00:00:09 /usr/local/pgsql/bin/postgres -D /u01/pgsql/bkp_data

Here,

/usr/local/pgsql/bin/postgres -D /u01/pgsql/bkp_data

/u01/pgsql/bkp_data → Database files Location.

/usr/local/pgsql/bin/ → Software installation location.

So, what is PostgreSQL database administration?

It is nothing but understanding the files and folders inside the above-mentioned folders both logically and physically. So, understand these two locations both logically and physically and you are done with your database administration.