Which one is created first? Database or Instance?

The Oracle database includes all the physical files belonging to the server while the Oracle instance will provide the interface between the user and the data he wants to manipulate. But I want to know which one is created first? I had thought the database should be created first, before the instance. But after I read this post [Creating a Database with the CREATE DATABASE Statement](https://docs.oracle.com/cd/E11882_01/server.112/e25494/create.htm#ADMIN11073) I think I am. Because the manual shows theses instructions: Step 5: (Windows Only) Create an Instance
Step 9: Issue the CREATE DATABASE statement