I see a navigation rail in material 3 specs: https://m3.material.io/components/navigation-rail/overview
But it doesn't seem to have a corresponding component for web/angular.
How to implement it with angular material 18?
As of today, the web reference for Material 3 Navigation Rail states planned. So it's not ready yet for web is my understanding.
The current closest thing you have to this is Angular Material SideNav.
Apart from this there is an open feature request you can vote on, for enabling this feature in angular material.
We could expect it to be implemented in upcoming versions of Angular, but it's a P5, so it does not have much priority.