what is hub site in sharepoint online or what is hub site association or Hub Sites in SharePoint:

what is hub site in sharepoint online or what is hub site association or Hub Sites in SharePoint:

SharePoint hub sites help you meet the needs of your organization by connecting and organizing sites based on project, department, division, region, etc

Advantages of Hub Sites:

1. Common News & Site Activity
2. Common Navigation & Branding
3. Search Across All Sites
4. Association with a hub does not change the permissions on a site. If you associate a site that has restricted access with a hub, only users who have access to the restricted site will see content rolled up on the hub. Information surfaced on the hub site is security trimmed: if you don't have access to the content, you won't see it. 

Limitations of Hub sites: 

1. An organization is limited to 2000 HUB sites
2. A site can only associate with a hub family. However, hub families can be connected to one another using links either on the page or in hub navigation

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