creating a database

The following documentation comment has been logged on the website:

Page: https://www.postgresql.org/docs/17/tutorial-createdb.html
Description:

Dear,

I was reading intro to setup of postgresql, and looking at 
https://www.postgresql.org/docs/current/tutorial-createdb.html#TUTORIAL-CREATEDB

Regarding the sentence "To create a new database, in this example named
mydb, you use the following command:" 
I guess this is on the server side, in a Linux shell or similar?
But it is not explicitly stated, and this section comes right after
explanation of client-server. 

I think this should be clarified in the text. 
And what also could be clarified: can a database only be created on the
server side? 
Or is there also a client (SQL) command to create a new database on the
server? 

best regards,
Raf