YugabyteDB is a distributed SQL database composed of one or more nodes. In YSQL you can list the nodes (hosts) in the cluster via the yb_servers() function.
yugabyte=# SELECT * FROM yb_servers() ORDER BY 1;
host | port | num_connections | node_type | cloud | region | zone | public_ip
----------------+------+-----------------+-----------+--------+-------------+-------+-----------
192.168.56.110 | 5433 | 0 | primary | cloud1 | datacenter1 | rack1 |
192.168.56.111 | 5433 | 0 | primary | cloud1 | datacenter1 | rack1 |
192.168.56.112 | 5433 | 0 | primary | cloud1 | datacenter1 | rack1 |
(3 rows)
Have Fun!