Skype for Business is Microsoft´s successor of its old Lync business communication software. In addition to classic 1:1 and group chats using text, audio and/or video, Skype for Business offers advanced conferencing and streaming solutions for large companies.
With Skype Meeting Broadcast organizations can broadcast meetings on the Internet to up to 10,000 people, who can attend from a browser on nearly any device.
It also offers public switched telephone network conferencing (PSTN) which allows people invited to a Skype for Business meeting in Office 365 to join in by dialing-in using a landline or mobile phone.
At the moment PSTN conferencing is provided by Microsoft via dial-in numbers for the US, UK, Germany, France, Netherlands, Sweden, Switzerland, Italy, Denmark, Spain, Belgium, Canada and Austria.
Skype for Business can also replace traditional phone-infrastructure with a service called Cloud PBX with PSTN Calling. As Microsoft explains It offers “the ability to make and receive traditional phone calls directly from their Skype for Business client, and to manage these calls with features like hold, resume, forward and transfer.”