Microsoft is releasing SharePoint Online hub sites, a new building block of the intranet. SharePoint Online hub sites bring together related sites to roll up news and activity, simplify search, and create cohesion with shared navigation and look-and-feel.
SharePoint hub sites enable you to organize your intranet by associating multiple team sites and communication sites together. This is an optional feature that has no effect on the user experience unless hub sites are created.
You can use SharePoint Online hub sites in Office 365 to organize concepts, teams, divisions, or resources throughout your organization. With this feature, you will be able to create one or more hub sites by converting an existing modern team site or communication site into a hub site by using Microsoft PowerShell, or you can create a brand new modern site and start from there. After a hub site is created, admin-approved site owners can associate existing team sites and communication sites to the hub site.
When this feature is made available to your organization, you will be able to convert existing sites into hub sites by using the SharePoint Online Management Shell (PowerShell for SharePoint in Office 365), and the following cmdlet: Register -SPOHubSites https://contoso.sharepoint.com/sites/Communications – (where ‘Communications’ is the existing site you would like to convert into a hub site).