I need to know how the structure of databases of Sharepoint works, what is any databases, when they are created and this kind of stuff... I'm using a Sharepoint 2016 on premises.
SharePoint Server farm creates 4 types of databases
- Configuration Database (SharePoint_Config )
- Central Admin Database (SharePoint_AdminContent_ )
- Service applications Database
- Content database
Configuration databases, central admin and service application database are created when we run SharePoint configuration wizard.
Configuration database - This database is default database which contains all the setup/configuration information of your SharePoint farm.
Central Admin database - this database holds all the data related to Central Admin Site collection.
Service applications Database - Based on what kind of service application is configured/enabled on your SharePoint Farm this databases are created. Like for e.g. if you have configured Search service application, around 4 databases related to SharePoint search would be created. some other examples of Service application databases are
App Management database
Business Data Connectivity service application database
Secure Store Service database
Usage and Health Data Collection database
Content databases - This are actual content database create when we create a web application. A single content database will hold data related to one or more site collection. A web application can have more than one Content databases, A single site collection data can only be stored in a single content database.
As suggested by Marek, for more information - You can go through this link.
I think most of it is documented here:
You asked for the 'structure' of SharePoint databases. This information is not public available. You didn't tell us what you want to achieve with the provided information. It is important to mention that any manual change to a SharePoint database will make your entire farm unsupported! You have a bunch of development possibilities to get and modify data in a supported way.