On March 14, 2017, Microsoft announced the General Availability of a new chat-based workspace app called Microsoft Teams.
From 2015 until August 2018, Skype for Business served as the main communication app in Microsoft Office 365 plans and was a major focus of development for the Microsoft team. This made it much easier to quickly create calls and meetings and introduced the ability for users to chat with people outside of their organization. Skype improved upon Lync in several ways, but the biggest change was its inclusion in Office 365 packages.
Skype for Business was introduced in April 2015 as a replacement for Microsoft Lync, a communication app that featured instant messaging, audio & video calls, and meetings.
