A SharePoint site helps groups of people (whether work teams or social groups) share information and collaborate together. It is a site that provides a central storage and collaboration space for documents, information, and ideas. It allows you to share ideas, store and share information such as event calendars, Web links, contacts, announcements, etc.
It allows integration with Microsoft Office and allows team members to create collaborative workspace sites which can be easily used to share and manage their team information.
SharePoint sites are interactive – members of the site can discuss ideas and contribute content, comment on discussions and review documents as well.
It is a central point which allows people to work together.