20 Jan How to create your Team Site with SharePoint Online
Create a SharePoint Online team site to provide a location where you and your team can work on projects and share information from anywhere on any device. A team site includes a group of related web pages, document libraries for files, lists for data management, and web parts that you can customize to meet your needs.
When you create a team site in Office 365, a corresponding Office 365 Group is automatically created and any users you add to your team site get added to the Office 365 Group. All members of the team site have access to the Office 365 Group and can create publishing pages, new document libraries, custom lists, and add or rearrange web parts on the team site as needed. There’s no need to create an email distribution list or a SharePoint group.
Read more here: Office Support