For more info please check the components's official demos & documentation demos & documentation

`<mat-toolbar>` is a container for headers, titles, or actions.

Single row: In the most situations, a toolbar will be placed at the top of your application and will only have a single row that includes the title of your application.

My Application
The Material Design specifications describe that toolbars can also have multiple rows. Creating toolbars with multiple rows in Angular Material can be done by placing `<mat-toolbar-row>` elements inside of a `<mat-toolbar>`.
First Row Second Row
Note: Placing content outside of a `<mat-toolbar-row>` when multiple rows are specified is not supported.
Custom Toolbar Second Line verified_user Third Line favorite delete