SharePoint is used differently by different teams and in different organizations. For some of us, SharePoint is a collaborative workspace. For others, SharePoint is simply a place to store documents, almost like a network share, and for others, SharePoint is a workflow engine that’s used to automate tasks that are done on an everyday basis, but SharePoint is more than any of these individual functions. SharePoint’s not an individual application like Microsoft Word or Microsoft Excel, or even a suite of applications, like Outlook. SharePoint is more than simply a program. SharePoint is a platform that organizations use to do the thing that SharePoint does best, which is to create powerful websites with features that allow you and I to work together in ways that we hadn’t previously imagined. SharePoint is installed on one of your organization’s servers. So, unlike an application like Word or Adobe Reader, we don’t install SharePoint locally on our desktop. Rather, we connect to SharePoint.
SharePoint uses role based access control, which allow SharePoint administrators to very precisely control access to SharePoint itself, to the sites within SharePoint and to different items like documents stored in sites