Skype for Business, formerly known as Microsoft Lync Server, is a unified communication platform that integrates common channels of business communication including instant message (IM), Voice Over IP (VOIP), file transfer, web conferencing, voice mail, video chat and other different activities.
Since Microsoft has acquired Skype in 2011 and changed Lync’s name to Skype for Business in 2015. Changes include a new client interface, a new server release and updates to the UC Service in Office 365. Skype for Business can be used for communication within organization, between multiple organization or with external individuals with Skype accounts.
Below is the video I hope this will help you to understand Skype for Business in better way 🙂