Microsoft has provided a face lift to SharePoint team sites that enables integration with Office Graph, provides an improved sites home page and integrates team sites with Office 365 groups.
New SharePoint Home Page
“Sites” is now “SharePoint” and the home page has been redesigned to make better suggestions as to sites you can follow and discover.
The new home page provides frequently updated sites, suggested sites based on Office Graph and sites you have explicitly followed.
With the new SharePoint mobile app, you can access the same list of sites through your mobile device.
New Default Team Site Home Page
The default team site now has an improved home page that surfaces content such as important documents and activities.
Office 365 Groups Now Provides a Full SharePoint Team Site
When you create an Office 365 Group, you now are provisioned a full SharePoint team site.
New Document Library UI with Support for Pinning
The document library in SharePoint UI has also been redesigned.
The new UI supports the ability to pin documents that are important and they show up at the top of the list.