Boards are in essence product roadmaps. You can call it a collection of Kanban boards. Only difference between these Kanban boards & the ones within Jira - these can be made publicly visible & purpose driven to communicate any kind of roadmap.
Any board can have multiple tabs & each board can have an additional set of configurations. Each board will appear as an independent public/private/restricted roadmap portal, depending on how it is set up.
On each board, you can add as many as tabs you want. These tabs will further have columns where Jira service project admin can add JQLs so relevant issue cards will be displayed in each column. For example, on a project roadmap, you can add a column to show features to be vetted, planned in next six months, features under development, etc.
Columns display all the cards depending on the added JQL by Jira service project admin. One can add as many columns as you want on each tab. Issue cards on these columns are auto managed based on JQLs. In these columns, you can see the list of issue cards, comments & votes by customers, users, etc.
This is provided by Atlassian's Jira service management. One can add a code snippet and embed Jira service desk portal right on the roadmap board. This way, it becomes easy for your roadmap audience to easily submit feedback and feature requests.
Sub-domain & Path
Sub-domain is derived from your Jira’s base url. e.g. our Jira is accessible on amoeboids.atlassian.net. Thus, in this case amoeboids acts as a sub-domain for the roadmap portals you create. And all your roadmap portals will begin with amoeboids.roadmapper.app/path
Path is the actual text that you can configure & it appears in the roadmap portal URL as highlighted above. This portal link can be added at multiple places to share it with customers, product users. For example, you can add the portal link on your website, blogs, within your product menu, etc so users can easily access your product roadmap portal.
If you do not wish to embed your Jira service desk portal via widget or wish to add some other relevant links on the roadmap board, you can add those links and display them on boards.