Postico is a database client. Postico can connect to a local PostgreSQL server running on your Mac, or to remote servers running on a different computer. If you want to install a local PostgreSQL server on your Mac, I recommend Postgres.app. Postgres.app starts a PostgreSQL server running locally on your Mac. The first time it starts it will automatically create a new data directory and set up an empty database. After a few moments, the server will be running and waiting for connections. Postgres.app can't start when another PostgreSQL server is already running on your computer. If you run into problems, make sure to deactivate or uninstall other PostgreSQL installations. Reboot your computer after uninstalling! To connect to a PostgreSQL server with Postico, you must first create a favorite. A favorite contains parameters for connecting to a server. Some connection parameters are optional.