SharePoint is a type of web application platform in the Microsoft Office server suite.
It was launched in the year 2001.
Microsoft SharePoint is a browser-based collaboration and document management platform from Microsoft - Wikipedia.
It allows groups to set up a centralized, password protected space for document sharing.

SharePoint combines various functions which are traditionally separate applications: intranet, extranet, content management, document management, personal cloud, enterprise social networking, enterprise search, business intelligence, workflow management, web content management, and an enterprise application store.

The most common uses of the SharePoint include:

Enterprise Content and Document Management
Personal Cloud
Intranet & Corporate Social Network
Extranet & Web Content Management
Software framework

SharePoint editions:

Microsoft SharePoint Foundation
Microsoft SharePoint Standard
Microsoft SharePoint Enterprise
SharePoint Online