I was watching this video about "Office 365 Groups" Office 365 Groups: Quick tour of new user and admin experiences.
But i am not sure what are the main differences between creating "Office 365 Groups" and between creating SharePoint sites (such as Team sites and adding the related users inside the site)?? are "Office 365 Groups" and SharePoint sites suppose to replace each other? or they serve different purpose and different business needs?
Thanks