If you've started a mysql session, but haven't connected to a particular database yet, you can list the available databases like so:
> show databases;
+-----------------------------+
| Database |
+-----------------------------+
| information_schema |
| my_app_dev |
+-----------------------------+If you are curious about the tables in a particular database, you can list them by specifying the database's name:
> show tables in my_app_dev;
+------------------------------+
| Tables_in_my_app_dev |
+------------------------------+
| pokemons |
| trainers |
+------------------------------+Alternatively, you can connect to the database of interest and then there is no need to specify the name of the database going forward.
> use my_app_dev;
> show tables;
+------------------------------+
| Tables_in_my_app_dev |
+------------------------------+
| pokemons |
| trainers |
+------------------------------+